From 55ce40d1519fff2766a075e5e5f099e61d58b7ae Mon Sep 17 00:00:00 2001
From: Yuki Wong <v-kaywon@microsoft.com>
Date: Tue, 9 Jul 2019 16:59:04 -0700
Subject: [PATCH 01/10] Update issue templates

---
 .github/ISSUE_TEMPLATE/custom.md | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 .github/ISSUE_TEMPLATE/custom.md

diff --git a/.github/ISSUE_TEMPLATE/custom.md b/.github/ISSUE_TEMPLATE/custom.md
new file mode 100644
index 00000000..48d5f81f
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/custom.md
@@ -0,0 +1,10 @@
+---
+name: Custom issue template
+about: Describe this issue template's purpose here.
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+

From 9ea2f0be6f269a539898d3aab78c067a2864fa77 Mon Sep 17 00:00:00 2001
From: Yuki Wong <v-kaywon@microsoft.com>
Date: Tue, 9 Jul 2019 17:04:05 -0700
Subject: [PATCH 02/10] Delete custom.md

---
 .github/ISSUE_TEMPLATE/custom.md | 10 ----------
 1 file changed, 10 deletions(-)
 delete mode 100644 .github/ISSUE_TEMPLATE/custom.md

diff --git a/.github/ISSUE_TEMPLATE/custom.md b/.github/ISSUE_TEMPLATE/custom.md
deleted file mode 100644
index 48d5f81f..00000000
--- a/.github/ISSUE_TEMPLATE/custom.md
+++ /dev/null
@@ -1,10 +0,0 @@
----
-name: Custom issue template
-about: Describe this issue template's purpose here.
-title: ''
-labels: ''
-assignees: ''
-
----
-
-

From b57a23fd32ea652bbba42374ec01c7f322cf7b48 Mon Sep 17 00:00:00 2001
From: v-kaywon <v-kaywon@microsoft.com>
Date: Wed, 11 Sep 2019 14:29:29 -0700
Subject: [PATCH 03/10] sub package out mssql specific types

---
 buf.go                                        |  32 ++--
 bulkcopy.go                                   |   6 +-
 datetimeoffset_example_test.go                |  10 +-
 error.go => internal/mssqlerror/error.go      |  17 +-
 internal/{decimal => mssqltypes}/decimal.go   |   2 +-
 .../{decimal => mssqltypes}/decimal_test.go   |   2 +-
 internal/mssqltypes/mssqltypes.go             |  20 ++
 .../mssqltypes/uniqueidentifier.go            |   6 +-
 .../mssqltypes/uniqueidentifier_test.go       |   2 +-
 mssql.go                                      |   3 +-
 mssql_go19.go                                 |  33 ++--
 queries_go110_test.go                         |  15 +-
 queries_go19_test.go                          |  25 +--
 queries_test.go                               |  13 +-
 token.go                                      | 110 +++++------
 tvp_go19_db_test.go                           | 174 +++++++++---------
 types.go                                      |  39 ++--
 17 files changed, 272 insertions(+), 237 deletions(-)
 rename error.go => internal/mssqlerror/error.go (64%)
 rename internal/{decimal => mssqltypes}/decimal.go (99%)
 rename internal/{decimal => mssqltypes}/decimal_test.go (99%)
 create mode 100644 internal/mssqltypes/mssqltypes.go
 rename uniqueidentifier.go => internal/mssqltypes/uniqueidentifier.go (85%)
 rename uniqueidentifier_test.go => internal/mssqltypes/uniqueidentifier_test.go (98%)

diff --git a/buf.go b/buf.go
index ba39b40f..d8252b84 100644
--- a/buf.go
+++ b/buf.go
@@ -4,6 +4,8 @@ import (
 	"encoding/binary"
 	"errors"
 	"io"
+
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 )
 
 type packetType uint8
@@ -186,7 +188,7 @@ func (r *tdsBuffer) ReadByte() (res byte, err error) {
 func (r *tdsBuffer) byte() byte {
 	b, err := r.ReadByte()
 	if err != nil {
-		badStreamPanic(err)
+		mssqlerror.BadStreamPanic(err)
 	}
 	return b
 }
@@ -194,7 +196,7 @@ func (r *tdsBuffer) byte() byte {
 func (r *tdsBuffer) ReadFull(buf []byte) {
 	_, err := io.ReadFull(r, buf[:])
 	if err != nil {
-		badStreamPanic(err)
+		mssqlerror.BadStreamPanic(err)
 	}
 }
 
@@ -221,27 +223,23 @@ func (r *tdsBuffer) uint16() uint16 {
 }
 
 func (r *tdsBuffer) BVarChar() string {
-	return readBVarCharOrPanic(r)
+	l := int(r.byte())
+	return r.readUcs2(l)
 }
 
-func readBVarCharOrPanic(r io.Reader) string {
-	s, err := readBVarChar(r)
-	if err != nil {
-		badStreamPanic(err)
-	}
-	return s
+func (r *tdsBuffer) UsVarChar() string {
+	l := int(r.uint16())
+	return r.readUcs2(l)
 }
 
-func readUsVarCharOrPanic(r io.Reader) string {
-	s, err := readUsVarChar(r)
+func (r *tdsBuffer) readUcs2(numchars int) string {
+	b := make([]byte, numchars*2)
+	r.ReadFull(b)
+	res, err := ucs22str(b)
 	if err != nil {
-		badStreamPanic(err)
+		mssqlerror.BadStreamPanic(err)
 	}
-	return s
-}
-
-func (r *tdsBuffer) UsVarChar() string {
-	return readUsVarCharOrPanic(r)
+	return res
 }
 
 func (r *tdsBuffer) Read(buf []byte) (copied int, err error) {
diff --git a/bulkcopy.go b/bulkcopy.go
index 3b7bbb44..c7e3e527 100644
--- a/bulkcopy.go
+++ b/bulkcopy.go
@@ -11,7 +11,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/denisenkom/go-mssqldb/internal/decimal"
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
 type Bulk struct {
@@ -483,8 +483,8 @@ func (b *Bulk) makeParam(val DataValue, col columnStruct) (res param, err error)
 
 		perc := col.ti.Prec
 		scale := col.ti.Scale
-		var dec decimal.Decimal
-		dec, err = decimal.Float64ToDecimalScale(value, scale)
+		var dec mssqltypes.Decimal
+		dec, err = mssqltypes.Float64ToDecimalScale(value, scale)
 		if err != nil {
 			return res, err
 		}
diff --git a/datetimeoffset_example_test.go b/datetimeoffset_example_test.go
index 186f8196..95a0de03 100644
--- a/datetimeoffset_example_test.go
+++ b/datetimeoffset_example_test.go
@@ -9,8 +9,8 @@ import (
 	"log"
 	"time"
 
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 	"github.com/golang-sql/civil"
-	"github.com/denisenkom/go-mssqldb"
 )
 
 // This example shows how to insert and retrieve date and time types data
@@ -56,9 +56,9 @@ func insertDateTime(db *sql.DB) {
 	var timeCol civil.Time = civil.TimeOf(tin)
 	var dateCol civil.Date = civil.DateOf(tin)
 	var smalldatetimeCol string = "2006-01-02 22:04:00"
-	var datetimeCol mssql.DateTime1 = mssql.DateTime1(tin)
+	var datetimeCol mssqltypes.DateTime1 = mssqltypes.DateTime1(tin)
 	var datetime2Col civil.DateTime = civil.DateTimeOf(tin)
-	var datetimeoffsetCol mssql.DateTimeOffset = mssql.DateTimeOffset(tin)
+	var datetimeoffsetCol mssqltypes.DateTimeOffset = mssqltypes.DateTimeOffset(tin)
 	_, err = stmt.Exec(timeCol, dateCol, smalldatetimeCol, datetimeCol, datetime2Col, datetimeoffsetCol)
 	if err != nil {
 		log.Fatal(err)
@@ -103,8 +103,8 @@ func retrieveDateTimeOutParam(db *sql.DB) {
 		log.Fatal(err)
 	}
 	var (
-		timeOutParam, datetime2OutParam, datetimeoffsetOutParam mssql.DateTimeOffset
-		dateOutParam, datetimeOutParam                          mssql.DateTime1
+		timeOutParam, datetime2OutParam, datetimeoffsetOutParam mssqltypes.DateTimeOffset
+		dateOutParam, datetimeOutParam                          mssqltypes.DateTime1
 		smalldatetimeOutParam                                   string
 	)
 	_, err = db.Exec("OutDatetimeProc",
diff --git a/error.go b/internal/mssqlerror/error.go
similarity index 64%
rename from error.go
rename to internal/mssqlerror/error.go
index 2e5bacee..fe4ce619 100644
--- a/error.go
+++ b/internal/mssqlerror/error.go
@@ -1,4 +1,4 @@
-package mssql
+package mssqlerror
 
 import (
 	"fmt"
@@ -19,6 +19,7 @@ type Error struct {
 	LineNo     int32
 }
 
+// Error returns the SQL Server error message.
 func (e Error) Error() string {
 	return "mssql: " + e.Message
 }
@@ -28,34 +29,42 @@ func (e Error) SQLErrorNumber() int32 {
 	return e.Number
 }
 
+// SQLErrorState returns the SQL Server error state.
 func (e Error) SQLErrorState() uint8 {
 	return e.State
 }
 
+// SQLErrorClass returns the SQL Server error class.
 func (e Error) SQLErrorClass() uint8 {
 	return e.Class
 }
 
+// SQLErrorMessage returns the SQL Server error message.
 func (e Error) SQLErrorMessage() string {
 	return e.Message
 }
 
+// SQLErrorServerName returns the SQL Server name.
 func (e Error) SQLErrorServerName() string {
 	return e.ServerName
 }
 
+// SQLErrorProcName returns the procedure name.
 func (e Error) SQLErrorProcName() string {
 	return e.ProcName
 }
 
+// SQLErrorLineNo returns the error line number.
 func (e Error) SQLErrorLineNo() int32 {
 	return e.LineNo
 }
 
+// StreamError represents TDS stream error.
 type StreamError struct {
 	Message string
 }
 
+// Error returns the TDS stream error message.
 func (e StreamError) Error() string {
 	return e.Message
 }
@@ -64,10 +73,12 @@ func streamErrorf(format string, v ...interface{}) StreamError {
 	return StreamError{"Invalid TDS stream: " + fmt.Sprintf(format, v...)}
 }
 
-func badStreamPanic(err error) {
+// BadStreamPanic calls panic with err.
+func BadStreamPanic(err error) {
 	panic(err)
 }
 
-func badStreamPanicf(format string, v ...interface{}) {
+// BadStreamPanicf calls panic with a formatted error message as an invalid TDS stream error.
+func BadStreamPanicf(format string, v ...interface{}) {
 	panic(streamErrorf(format, v...))
 }
diff --git a/internal/decimal/decimal.go b/internal/mssqltypes/decimal.go
similarity index 99%
rename from internal/decimal/decimal.go
rename to internal/mssqltypes/decimal.go
index 68f790a0..3bafb65a 100644
--- a/internal/decimal/decimal.go
+++ b/internal/mssqltypes/decimal.go
@@ -1,4 +1,4 @@
-package decimal
+package mssqltypes
 
 import (
 	"encoding/binary"
diff --git a/internal/decimal/decimal_test.go b/internal/mssqltypes/decimal_test.go
similarity index 99%
rename from internal/decimal/decimal_test.go
rename to internal/mssqltypes/decimal_test.go
index f59b06c3..9d18e768 100644
--- a/internal/decimal/decimal_test.go
+++ b/internal/mssqltypes/decimal_test.go
@@ -1,4 +1,4 @@
-package decimal
+package mssqltypes
 
 import (
 	"math"
diff --git a/internal/mssqltypes/mssqltypes.go b/internal/mssqltypes/mssqltypes.go
new file mode 100644
index 00000000..92b04b3c
--- /dev/null
+++ b/internal/mssqltypes/mssqltypes.go
@@ -0,0 +1,20 @@
+// +build go1.9
+
+package mssqltypes
+
+import "time"
+
+// VarChar parameter types.
+type VarChar string
+
+// NVarCharMax encodes parameters to NVarChar(max) SQL type.
+type NVarCharMax string
+
+// VarCharMax encodes parameter to VarChar(max) SQL type.
+type VarCharMax string
+
+// DateTime1 encodes parameters to original DateTime SQL types.
+type DateTime1 time.Time
+
+// DateTimeOffset encodes parameters to DateTimeOffset, preserving the UTC offset.
+type DateTimeOffset time.Time
diff --git a/uniqueidentifier.go b/internal/mssqltypes/uniqueidentifier.go
similarity index 85%
rename from uniqueidentifier.go
rename to internal/mssqltypes/uniqueidentifier.go
index c8ef3149..39a28ead 100644
--- a/uniqueidentifier.go
+++ b/internal/mssqltypes/uniqueidentifier.go
@@ -1,4 +1,4 @@
-package mssql
+package mssqltypes
 
 import (
 	"database/sql/driver"
@@ -7,8 +7,10 @@ import (
 	"fmt"
 )
 
+// UniqueIdentifier encodes parameters to Uniqueidentifier SQL type.
 type UniqueIdentifier [16]byte
 
+// Scan converts v to UniqueIdentifier
 func (u *UniqueIdentifier) Scan(v interface{}) error {
 	reverse := func(b []byte) {
 		for i, j := 0, len(b)-1; i < j; i, j = i+1, j-1 {
@@ -52,6 +54,7 @@ func (u *UniqueIdentifier) Scan(v interface{}) error {
 	}
 }
 
+// Value converts UniqueIdentifier to bytes
 func (u UniqueIdentifier) Value() (driver.Value, error) {
 	reverse := func(b []byte) {
 		for i, j := 0, len(b)-1; i < j; i, j = i+1, j-1 {
@@ -69,6 +72,7 @@ func (u UniqueIdentifier) Value() (driver.Value, error) {
 	return raw, nil
 }
 
+// String converts UniqueIdentifier to string
 func (u UniqueIdentifier) String() string {
 	return fmt.Sprintf("%X-%X-%X-%X-%X", u[0:4], u[4:6], u[6:8], u[8:10], u[10:])
 }
diff --git a/uniqueidentifier_test.go b/internal/mssqltypes/uniqueidentifier_test.go
similarity index 98%
rename from uniqueidentifier_test.go
rename to internal/mssqltypes/uniqueidentifier_test.go
index 2a29133a..22249614 100644
--- a/uniqueidentifier_test.go
+++ b/internal/mssqltypes/uniqueidentifier_test.go
@@ -1,4 +1,4 @@
-package mssql
+package mssqltypes
 
 import (
 	"bytes"
diff --git a/mssql.go b/mssql.go
index e37109cd..2949163d 100644
--- a/mssql.go
+++ b/mssql.go
@@ -15,6 +15,7 @@ import (
 	"time"
 	"unicode"
 
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 	"github.com/denisenkom/go-mssqldb/internal/querytext"
 )
 
@@ -188,7 +189,7 @@ func (c *Conn) checkBadConn(err error) error {
 	case net.Error:
 		c.connectionGood = false
 		return err
-	case StreamError:
+	case mssqlerror.StreamError:
 		c.connectionGood = false
 		return err
 	default:
diff --git a/mssql_go19.go b/mssql_go19.go
index a2bd1167..170a2a0d 100644
--- a/mssql_go19.go
+++ b/mssql_go19.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	// "github.com/cockroachdb/apd"
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 	"github.com/golang-sql/civil"
 )
 
@@ -26,29 +27,17 @@ type MssqlStmt = Stmt               // Deprecated: users should transition to th
 
 var _ driver.NamedValueChecker = &Conn{}
 
-// VarChar parameter types.
-type VarChar string
-
-type NVarCharMax string
-type VarCharMax string
-
-// DateTime1 encodes parameters to original DateTime SQL types.
-type DateTime1 time.Time
-
-// DateTimeOffset encodes parameters to DateTimeOffset, preserving the UTC offset.
-type DateTimeOffset time.Time
-
 func convertInputParameter(val interface{}) (interface{}, error) {
 	switch v := val.(type) {
-	case VarChar:
+	case mssqltypes.VarChar:
 		return val, nil
-	case NVarCharMax:
+	case mssqltypes.NVarCharMax:
 		return val, nil
-	case VarCharMax:
+	case mssqltypes.VarCharMax:
 		return val, nil
-	case DateTime1:
+	case mssqltypes.DateTime1:
 		return val, nil
-	case DateTimeOffset:
+	case mssqltypes.DateTimeOffset:
 		return val, nil
 	case civil.Date:
 		return val, nil
@@ -123,24 +112,24 @@ func (c *Conn) CheckNamedValue(nv *driver.NamedValue) error {
 
 func (s *Stmt) makeParamExtra(val driver.Value) (res param, err error) {
 	switch val := val.(type) {
-	case VarChar:
+	case mssqltypes.VarChar:
 		res.ti.TypeId = typeBigVarChar
 		res.buffer = []byte(val)
 		res.ti.Size = len(res.buffer)
-	case VarCharMax:
+	case mssqltypes.VarCharMax:
 		res.ti.TypeId = typeBigVarChar
 		res.buffer = []byte(val)
 		res.ti.Size = 0 // currently zero forces varchar(max)
-	case NVarCharMax:
+	case mssqltypes.NVarCharMax:
 		res.ti.TypeId = typeNVarChar
 		res.buffer = str2ucs2(string(val))
 		res.ti.Size = 0 // currently zero forces nvarchar(max)
-	case DateTime1:
+	case mssqltypes.DateTime1:
 		t := time.Time(val)
 		res.ti.TypeId = typeDateTimeN
 		res.buffer = encodeDateTime(t)
 		res.ti.Size = len(res.buffer)
-	case DateTimeOffset:
+	case mssqltypes.DateTimeOffset:
 		res.ti.TypeId = typeDateTimeOffsetN
 		res.ti.Scale = 7
 		res.buffer = encodeDateTimeOffset(time.Time(val), int(res.ti.Scale))
diff --git a/queries_go110_test.go b/queries_go110_test.go
index debb636f..f7e7b16e 100644
--- a/queries_go110_test.go
+++ b/queries_go110_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 	"github.com/golang-sql/civil"
 )
 
@@ -80,14 +81,14 @@ select
 ;
 	`,
 		sql.Named("nv", "base type nvarchar"),
-		sql.Named("v", VarChar("base type varchar")),
-		sql.Named("nvcm", NVarCharMax(strings.Repeat("x", 5000))),
-		sql.Named("vcm", VarCharMax(strings.Repeat("x", 5000))),
-		sql.Named("dt1", DateTime1(tin)),
+		sql.Named("v", mssqltypes.VarChar("base type varchar")),
+		sql.Named("nvcm", mssqltypes.NVarCharMax(strings.Repeat("x", 5000))),
+		sql.Named("vcm", mssqltypes.VarCharMax(strings.Repeat("x", 5000))),
+		sql.Named("dt1", mssqltypes.DateTime1(tin)),
 		sql.Named("dt2", civil.DateTimeOf(tin)),
 		sql.Named("d", civil.DateOf(tin)),
 		sql.Named("tm", civil.TimeOf(tin)),
-		sql.Named("dto", DateTimeOffset(tin)),
+		sql.Named("dto", mssqltypes.DateTimeOffset(tin)),
 	)
 	err = row.Scan(&nv, &v, &nvcm, &vcm, &dt1, &dt2, &d, &tm, &dto)
 	if err != nil {
@@ -153,11 +154,11 @@ select
 		sql.Named("nv", sin),
 		sql.Named("v", sin),
 		sql.Named("tgo", tin),
-		sql.Named("dt1", DateTime1(tin)),
+		sql.Named("dt1", mssqltypes.DateTime1(tin)),
 		sql.Named("dt2", civil.DateTimeOf(tin)),
 		sql.Named("d", civil.DateOf(tin)),
 		sql.Named("tm", civil.TimeOf(tin)),
-		sql.Named("dto", DateTimeOffset(tin)),
+		sql.Named("dto", mssqltypes.DateTimeOffset(tin)),
 	).Scan(&nv, &v, &tgo, &dt1, &dt2, &d, &tm, &dto)
 	if err != nil {
 		t.Fatal(err)
diff --git a/queries_go19_test.go b/queries_go19_test.go
index e3addd03..5e86818d 100644
--- a/queries_go19_test.go
+++ b/queries_go19_test.go
@@ -10,6 +10,9 @@ import (
 	"regexp"
 	"testing"
 	"time"
+
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
 func TestOutputParam(t *testing.T) {
@@ -174,8 +177,8 @@ END;
 			if err != nil {
 				t.Fatal(err)
 			}
-			var datetime_param DateTime1
-			datetime_param = DateTime1(tin)
+			var datetime_param mssqltypes.DateTime1
+			datetime_param = mssqltypes.DateTime1(tin)
 			_, err = db.ExecContext(ctx, sqltextrun,
 				sql.Named("datetime", sql.Out{Dest: &datetime_param}),
 			)
@@ -224,7 +227,7 @@ END;
 
 		t.Run("should fail if destination has invalid type", func(t *testing.T) {
 			// Error type should not be supported
-			var err_out Error
+			var err_out mssqlerror.Error
 			_, err := db.ExecContext(ctx, sqltextrun,
 				sql.Named("bid", sql.Out{Dest: &err_out}),
 			)
@@ -244,7 +247,7 @@ END;
 
 		t.Run("should fail if parameter has invalid type", func(t *testing.T) {
 			// passing invalid parameter type
-			var err_val Error
+			var err_val mssqlerror.Error
 			_, err = db.ExecContext(ctx, sqltextrun, err_val)
 			if err == nil {
 				t.Error("Expected to fail but it didn't")
@@ -346,7 +349,7 @@ END;
 	t.Run("original test", func(t *testing.T) {
 		var bout int64 = 3
 		var cout string
-		var vout VarChar
+		var vout mssqltypes.VarChar
 		_, err = db.ExecContext(ctx, sqltextrun,
 			sql.Named("aid", 5),
 			sql.Named("bid", sql.Out{Dest: &bout}),
@@ -964,12 +967,12 @@ func TestDateTimeParam19(t *testing.T) {
 	var emptydate time.Time
 	mindate1 := time.Date(1753, 1, 1, 0, 0, 0, 0, time.UTC)
 	maxdate1 := time.Date(9999, 12, 31, 23, 59, 59, 997000000, time.UTC)
-	testdates1 := []DateTime1{
-		DateTime1(mindate1),
-		DateTime1(maxdate1),
-		DateTime1(time.Date(1752, 12, 31, 23, 59, 59, 997000000, time.UTC)), // just a little below minimum date
-		DateTime1(time.Date(10000, 1, 1, 0, 0, 0, 0, time.UTC)),             // just a little over maximum date
-		DateTime1(emptydate),
+	testdates1 := []mssqltypes.DateTime1{
+		mssqltypes.DateTime1(mindate1),
+		mssqltypes.DateTime1(maxdate1),
+		mssqltypes.DateTime1(time.Date(1752, 12, 31, 23, 59, 59, 997000000, time.UTC)), // just a little below minimum date
+		mssqltypes.DateTime1(time.Date(10000, 1, 1, 0, 0, 0, 0, time.UTC)),             // just a little over maximum date
+		mssqltypes.DateTime1(emptydate),
 	}
 
 	for _, test := range testdates1 {
diff --git a/queries_test.go b/queries_test.go
index 2b476a84..1098899a 100644
--- a/queries_test.go
+++ b/queries_test.go
@@ -14,6 +14,9 @@ import (
 	"sync"
 	"testing"
 	"time"
+
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
 func driverWithProcess(t *testing.T) *Driver {
@@ -619,7 +622,7 @@ func TestError(t *testing.T) {
 		t.Fatal("Query should fail")
 	}
 
-	if sqlerr, ok := err.(Error); !ok {
+	if sqlerr, ok := err.(mssqlerror.Error); !ok {
 		t.Fatalf("Should be sql error, actually %T, %v", err, err)
 	} else {
 		if sqlerr.Number != 2812 { // Could not find stored procedure 'bad'
@@ -836,7 +839,7 @@ func TestUniqueIdentifierParam(t *testing.T) {
 		uuid interface{}
 	}
 
-	expected := UniqueIdentifier{0x01, 0x23, 0x45, 0x67,
+	expected := mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67,
 		0x89, 0xAB,
 		0xCD, 0xEF,
 		0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF,
@@ -856,7 +859,7 @@ func TestUniqueIdentifierParam(t *testing.T) {
 
 	for _, test := range values {
 		t.Run(test.name, func(t *testing.T) {
-			var uuid2 UniqueIdentifier
+			var uuid2 mssqltypes.UniqueIdentifier
 			err := conn.QueryRow("select ?", test.uuid).Scan(&uuid2)
 			if err != nil {
 				t.Fatal("select / scan failed", err.Error())
@@ -969,7 +972,7 @@ func TestErrorInfo(t *testing.T) {
 	defer conn.Close()
 
 	_, err := conn.Exec("select bad")
-	if sqlError, ok := err.(Error); ok {
+	if sqlError, ok := err.(mssqlerror.Error); ok {
 		if sqlError.SQLErrorNumber() != 207 /*invalid column name*/ {
 			t.Errorf("Query failed with unexpected error number %d %s", sqlError.SQLErrorNumber(), sqlError.SQLErrorMessage())
 		}
@@ -980,7 +983,7 @@ func TestErrorInfo(t *testing.T) {
 		t.Error("Failed to convert error to SQLErorr", err)
 	}
 	_, err = conn.Exec("RAISERROR('test message', 18, 111)")
-	if sqlError, ok := err.(Error); ok {
+	if sqlError, ok := err.(mssqlerror.Error); ok {
 		if sqlError.SQLErrorNumber() != 50000 {
 			t.Errorf("Query failed with unexpected error number %d %s", sqlError.SQLErrorNumber(), sqlError.SQLErrorMessage())
 		}
diff --git a/token.go b/token.go
index 1acac8a5..7b4bd4f0 100644
--- a/token.go
+++ b/token.go
@@ -9,6 +9,8 @@ import (
 	"net"
 	"strconv"
 	"strings"
+
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 )
 
 //go:generate stringer -type token
@@ -87,18 +89,18 @@ type doneStruct struct {
 	Status   uint16
 	CurCmd   uint16
 	RowCount uint64
-	errors   []Error
+	errors   []mssqlerror.Error
 }
 
 func (d doneStruct) isError() bool {
 	return d.Status&doneError != 0 || len(d.errors) > 0
 }
 
-func (d doneStruct) getError() Error {
+func (d doneStruct) getError() mssqlerror.Error {
 	if len(d.errors) > 0 {
 		return d.errors[len(d.errors)-1]
 	} else {
-		return Error{Message: "Request failed but didn't provide reason"}
+		return mssqlerror.Error{Message: "Request failed but didn't provide reason"}
 	}
 }
 
@@ -137,127 +139,127 @@ func processEnvChg(sess *tdsSession) {
 			return
 		}
 		if err != nil {
-			badStreamPanic(err)
+			mssqlerror.BadStreamPanic(err)
 		}
 		switch envtype {
 		case envTypDatabase:
 			sess.database, err = readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			_, err = readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTypLanguage:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTypCharset:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTypPacketSize:
 			packetsize, err := readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			_, err = readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			packetsizei, err := strconv.Atoi(packetsize)
 			if err != nil {
-				badStreamPanicf("Invalid Packet size value returned from server (%s): %s", packetsize, err.Error())
+				mssqlerror.BadStreamPanicf("Invalid Packet size value returned from server (%s): %s", packetsize, err.Error())
 			}
 			sess.buf.ResizeBuffer(packetsizei)
 		case envSortId:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envSortFlags:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envSqlCollation:
 			// currently ignored
 			var collationSize uint8
 			err = binary.Read(r, binary.LittleEndian, &collationSize)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 
 			// SQL Collation data should contain 5 bytes in length
 			if collationSize != 5 {
-				badStreamPanicf("Invalid SQL Collation size value returned from server: %d", collationSize)
+				mssqlerror.BadStreamPanicf("Invalid SQL Collation size value returned from server: %d", collationSize)
 			}
 
 			// 4 bytes, contains: LCID ColFlags Version
 			var info uint32
 			err = binary.Read(r, binary.LittleEndian, &info)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 
 			// 1 byte, contains: sortID
 			var sortID uint8
 			err = binary.Read(r, binary.LittleEndian, &sortID)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTypBeginTran:
 			tranid, err := readBVarByte(r)
 			if len(tranid) != 8 {
-				badStreamPanicf("invalid size of transaction identifier: %d", len(tranid))
+				mssqlerror.BadStreamPanicf("invalid size of transaction identifier: %d", len(tranid))
 			}
 			sess.tranid = binary.LittleEndian.Uint64(tranid)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			if sess.logFlags&logTransaction != 0 {
 				sess.log.Printf("BEGIN TRANSACTION %x\n", sess.tranid)
 			}
 			_, err = readBVarByte(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTypCommitTran, envTypRollbackTran:
 			_, err = readBVarByte(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			_, err = readBVarByte(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			if sess.logFlags&logTransaction != 0 {
 				if envtype == envTypCommitTran {
@@ -271,81 +273,81 @@ func processEnvChg(sess *tdsSession) {
 			// currently ignored
 			// new value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envDefectTran:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envDatabaseMirrorPartner:
 			sess.partner, err = readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			_, err = readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envPromoteTran:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// dtc token
 			// spec says it should be L_VARBYTE, so this code might be wrong
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTranMgrAddr:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// XACT_MANAGER_ADDRESS = B_VARBYTE
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTranEnded:
 			// currently ignored
 			// old value, B_VARBYTE
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envResetConnAck:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envStartedInstanceName:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// instance name
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envRouting:
 			// RoutingData message is:
@@ -355,24 +357,24 @@ func processEnvChg(sess *tdsSession) {
 			// AlternateServer             US_VARCHAR
 			_, err := readUshort(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			protocol, err := readByte(r)
 			if err != nil || protocol != 0 {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			newPort, err := readUshort(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			newServer, err := readUsVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// consume the OLDVALUE = %x00 %x00
 			_, err = readUshort(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			sess.routedServer = newServer
 			sess.routedPort = newPort
@@ -441,7 +443,7 @@ func parseLoginAck(r *tdsBuffer) loginAckStruct {
 	prognamelen := buf[1+4]
 	var err error
 	if res.ProgName, err = ucs22str(buf[1+4+1 : 1+4+1+prognamelen*2]); err != nil {
-		badStreamPanic(err)
+		mssqlerror.BadStreamPanic(err)
 	}
 	res.ProgVer = binary.BigEndian.Uint32(buf[size-4:])
 	return res
@@ -489,7 +491,7 @@ func parseNbcRow(r *tdsBuffer, columns []columnStruct, row []interface{}) {
 }
 
 // http://msdn.microsoft.com/en-us/library/dd304156.aspx
-func parseError72(r *tdsBuffer) (res Error) {
+func parseError72(r *tdsBuffer) (res mssqlerror.Error) {
 	length := r.uint16()
 	_ = length // ignore length
 	res.Number = r.int32()
@@ -503,7 +505,7 @@ func parseError72(r *tdsBuffer) (res Error) {
 }
 
 // http://msdn.microsoft.com/en-us/library/dd304156.aspx
-func parseInfo(r *tdsBuffer) (res Error) {
+func parseInfo(r *tdsBuffer) (res mssqlerror.Error) {
 	length := r.uint16()
 	_ = length // ignore length
 	res.Number = r.int32()
@@ -558,10 +560,10 @@ func processSingleResponse(sess *tdsSession, ch chan tokenStruct, outs map[strin
 		return
 	}
 	if packet_type != packReply {
-		badStreamPanic(fmt.Errorf("unexpected packet type in reply: got %v, expected %v", packet_type, packReply))
+		mssqlerror.BadStreamPanic(fmt.Errorf("unexpected packet type in reply: got %v, expected %v", packet_type, packReply))
 	}
 	var columns []columnStruct
-	errs := make([]Error, 0, 5)
+	errs := make([]mssqlerror.Error, 0, 5)
 	for {
 		token := token(sess.buf.byte())
 		if sess.logFlags&logDebug != 0 {
@@ -646,7 +648,7 @@ func processSingleResponse(sess *tdsSession, ch chan tokenStruct, outs map[strin
 				}
 			}
 		default:
-			badStreamPanic(fmt.Errorf("unknown token type returned: %v", token))
+			mssqlerror.BadStreamPanic(fmt.Errorf("unknown token type returned: %v", token))
 		}
 	}
 }
diff --git a/tvp_go19_db_test.go b/tvp_go19_db_test.go
index 6cf42641..d5f33db0 100644
--- a/tvp_go19_db_test.go
+++ b/tvp_go19_db_test.go
@@ -9,6 +9,8 @@ import (
 	"reflect"
 	"testing"
 	"time"
+
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
 const (
@@ -40,87 +42,87 @@ const (
 )
 
 type TvptableRow struct {
-	PBinary       []byte            `db:"p_binary"`
-	PVarchar      string            `db:"p_varchar"`
-	PVarcharNull  *string           `db:"p_varcharNull"`
-	PNvarchar     string            `db:"p_nvarchar"`
-	PNvarcharNull *string           `db:"p_nvarcharNull"`
-	PID           UniqueIdentifier  `db:"p_id"`
-	PIDNull       *UniqueIdentifier `db:"p_idNull"`
-	PVarbinary    []byte            `db:"p_varbinary"`
-	PTinyint      int8              `db:"p_tinyint"`
-	PTinyintNull  *int8             `db:"p_tinyintNull"`
-	PSmallint     int16             `db:"p_smallint"`
-	PSmallintNull *int16            `db:"p_smallintNull"`
-	PInt          int32             `db:"p_int"`
-	PIntNull      *int32            `db:"p_intNull"`
-	PBigint       int64             `db:"p_bigint"`
-	PBigintNull   *int64            `db:"p_bigintNull"`
-	PBit          bool              `db:"p_bit"`
-	PBitNull      *bool             `db:"p_bitNull"`
-	PFloat32      float32           `db:"p_float32"`
-	PFloatNull32  *float32          `db:"p_floatNull32"`
-	PFloat64      float64           `db:"p_float64"`
-	PFloatNull64  *float64          `db:"p_floatNull64"`
-	DTime         time.Time         `db:"p_timeNull"`
-	DTimeNull     *time.Time        `db:"p_time"`
-	Pint          int               `db:"pInt"`
-	PintNull      *int              `db:"pIntNull"`
+	PBinary       []byte                       `db:"p_binary"`
+	PVarchar      string                       `db:"p_varchar"`
+	PVarcharNull  *string                      `db:"p_varcharNull"`
+	PNvarchar     string                       `db:"p_nvarchar"`
+	PNvarcharNull *string                      `db:"p_nvarcharNull"`
+	PID           mssqltypes.UniqueIdentifier  `db:"p_id"`
+	PIDNull       *mssqltypes.UniqueIdentifier `db:"p_idNull"`
+	PVarbinary    []byte                       `db:"p_varbinary"`
+	PTinyint      int8                         `db:"p_tinyint"`
+	PTinyintNull  *int8                        `db:"p_tinyintNull"`
+	PSmallint     int16                        `db:"p_smallint"`
+	PSmallintNull *int16                       `db:"p_smallintNull"`
+	PInt          int32                        `db:"p_int"`
+	PIntNull      *int32                       `db:"p_intNull"`
+	PBigint       int64                        `db:"p_bigint"`
+	PBigintNull   *int64                       `db:"p_bigintNull"`
+	PBit          bool                         `db:"p_bit"`
+	PBitNull      *bool                        `db:"p_bitNull"`
+	PFloat32      float32                      `db:"p_float32"`
+	PFloatNull32  *float32                     `db:"p_floatNull32"`
+	PFloat64      float64                      `db:"p_float64"`
+	PFloatNull64  *float64                     `db:"p_floatNull64"`
+	DTime         time.Time                    `db:"p_timeNull"`
+	DTimeNull     *time.Time                   `db:"p_time"`
+	Pint          int                          `db:"pInt"`
+	PintNull      *int                         `db:"pIntNull"`
 }
 
 type TvptableRowWithSkipTag struct {
-	PBinary           []byte            `db:"p_binary"`
-	SkipPBinary       []byte            `json:"-"`
-	PVarchar          string            `db:"p_varchar"`
-	SkipPVarchar      string            `tvp:"-"`
-	PVarcharNull      *string           `db:"p_varcharNull"`
-	SkipPVarcharNull  *string           `json:"-" tvp:"-"`
-	PNvarchar         string            `db:"p_nvarchar"`
-	SkipPNvarchar     string            `json:"-"`
-	PNvarcharNull     *string           `db:"p_nvarcharNull"`
-	SkipPNvarcharNull *string           `json:"-"`
-	PID               UniqueIdentifier  `db:"p_id"`
-	SkipPID           UniqueIdentifier  `json:"-"`
-	PIDNull           *UniqueIdentifier `db:"p_idNull"`
-	SkipPIDNull       *UniqueIdentifier `tvp:"-"`
-	PVarbinary        []byte            `db:"p_varbinary"`
-	SkipPVarbinary    []byte            `json:"-" tvp:"-"`
-	PTinyint          int8              `db:"p_tinyint"`
-	SkipPTinyint      int8              `tvp:"-"`
-	PTinyintNull      *int8             `db:"p_tinyintNull"`
-	SkipPTinyintNull  *int8             `tvp:"-" json:"any"`
-	PSmallint         int16             `db:"p_smallint"`
-	SkipPSmallint     int16             `json:"-"`
-	PSmallintNull     *int16            `db:"p_smallintNull"`
-	SkipPSmallintNull *int16            `tvp:"-"`
-	PInt              int32             `db:"p_int"`
-	SkipPInt          int32             `json:"-"`
-	PIntNull          *int32            `db:"p_intNull"`
-	SkipPIntNull      *int32            `tvp:"-"`
-	PBigint           int64             `db:"p_bigint"`
-	SkipPBigint       int64             `tvp:"-"`
-	PBigintNull       *int64            `db:"p_bigintNull"`
-	SkipPBigintNull   *int64            `json:"any" tvp:"-"`
-	PBit              bool              `db:"p_bit"`
-	SkipPBit          bool              `json:"-"`
-	PBitNull          *bool             `db:"p_bitNull"`
-	SkipPBitNull      *bool             `json:"-"`
-	PFloat32          float32           `db:"p_float32"`
-	SkipPFloat32      float32           `tvp:"-"`
-	PFloatNull32      *float32          `db:"p_floatNull32"`
-	SkipPFloatNull32  *float32          `tvp:"-"`
-	PFloat64          float64           `db:"p_float64"`
-	SkipPFloat64      float64           `tvp:"-"`
-	PFloatNull64      *float64          `db:"p_floatNull64"`
-	SkipPFloatNull64  *float64          `tvp:"-"`
-	DTime             time.Time         `db:"p_timeNull"`
-	SkipDTime         time.Time         `tvp:"-"`
-	DTimeNull         *time.Time        `db:"p_time"`
-	SkipDTimeNull     *time.Time        `tvp:"-"`
-	Pint              int               `db:"p_int_null"`
-	SkipPint          int               `tvp:"-"`
-	PintNull          *int              `db:"p_int_"`
-	SkipPintNull      *int              `tvp:"-"`
+	PBinary           []byte                       `db:"p_binary"`
+	SkipPBinary       []byte                       `json:"-"`
+	PVarchar          string                       `db:"p_varchar"`
+	SkipPVarchar      string                       `tvp:"-"`
+	PVarcharNull      *string                      `db:"p_varcharNull"`
+	SkipPVarcharNull  *string                      `json:"-" tvp:"-"`
+	PNvarchar         string                       `db:"p_nvarchar"`
+	SkipPNvarchar     string                       `json:"-"`
+	PNvarcharNull     *string                      `db:"p_nvarcharNull"`
+	SkipPNvarcharNull *string                      `json:"-"`
+	PID               mssqltypes.UniqueIdentifier  `db:"p_id"`
+	SkipPID           mssqltypes.UniqueIdentifier  `json:"-"`
+	PIDNull           *mssqltypes.UniqueIdentifier `db:"p_idNull"`
+	SkipPIDNull       *mssqltypes.UniqueIdentifier `tvp:"-"`
+	PVarbinary        []byte                       `db:"p_varbinary"`
+	SkipPVarbinary    []byte                       `json:"-" tvp:"-"`
+	PTinyint          int8                         `db:"p_tinyint"`
+	SkipPTinyint      int8                         `tvp:"-"`
+	PTinyintNull      *int8                        `db:"p_tinyintNull"`
+	SkipPTinyintNull  *int8                        `tvp:"-" json:"any"`
+	PSmallint         int16                        `db:"p_smallint"`
+	SkipPSmallint     int16                        `json:"-"`
+	PSmallintNull     *int16                       `db:"p_smallintNull"`
+	SkipPSmallintNull *int16                       `tvp:"-"`
+	PInt              int32                        `db:"p_int"`
+	SkipPInt          int32                        `json:"-"`
+	PIntNull          *int32                       `db:"p_intNull"`
+	SkipPIntNull      *int32                       `tvp:"-"`
+	PBigint           int64                        `db:"p_bigint"`
+	SkipPBigint       int64                        `tvp:"-"`
+	PBigintNull       *int64                       `db:"p_bigintNull"`
+	SkipPBigintNull   *int64                       `json:"any" tvp:"-"`
+	PBit              bool                         `db:"p_bit"`
+	SkipPBit          bool                         `json:"-"`
+	PBitNull          *bool                        `db:"p_bitNull"`
+	SkipPBitNull      *bool                        `json:"-"`
+	PFloat32          float32                      `db:"p_float32"`
+	SkipPFloat32      float32                      `tvp:"-"`
+	PFloatNull32      *float32                     `db:"p_floatNull32"`
+	SkipPFloatNull32  *float32                     `tvp:"-"`
+	PFloat64          float64                      `db:"p_float64"`
+	SkipPFloat64      float64                      `tvp:"-"`
+	PFloatNull64      *float64                     `db:"p_floatNull64"`
+	SkipPFloatNull64  *float64                     `tvp:"-"`
+	DTime             time.Time                    `db:"p_timeNull"`
+	SkipDTime         time.Time                    `tvp:"-"`
+	DTimeNull         *time.Time                   `db:"p_time"`
+	SkipDTimeNull     *time.Time                   `tvp:"-"`
+	Pint              int                          `db:"p_int_null"`
+	SkipPint          int                          `tvp:"-"`
+	PintNull          *int                         `db:"p_int_"`
+	SkipPintNull      *int                         `tvp:"-"`
 }
 
 func TestTVP(t *testing.T) {
@@ -215,7 +217,7 @@ func TestTVP(t *testing.T) {
 			PBinary:    []byte("ccc"),
 			PVarchar:   varcharNull,
 			PNvarchar:  nvarchar,
-			PID:        UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PID:        mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PVarbinary: bytesMock,
 			PTinyint:   i8,
 			PSmallint:  i16,
@@ -231,7 +233,7 @@ func TestTVP(t *testing.T) {
 			PBinary:    []byte("www"),
 			PVarchar:   "eee",
 			PNvarchar:  "lll",
-			PID:        UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PID:        mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PVarbinary: []byte("zzz"),
 			PTinyint:   5,
 			PSmallint:  16000,
@@ -247,7 +249,7 @@ func TestTVP(t *testing.T) {
 			PBinary:       nil,
 			PVarcharNull:  &varcharNull,
 			PNvarcharNull: &nvarchar,
-			PIDNull:       &UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PIDNull:       &mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PTinyintNull:  &i8,
 			PSmallintNull: &i16,
 			PIntNull:      &i32,
@@ -263,7 +265,7 @@ func TestTVP(t *testing.T) {
 			PBinary:       []byte("www"),
 			PVarchar:      "eee",
 			PNvarchar:     "lll",
-			PIDNull:       &UniqueIdentifier{},
+			PIDNull:       &mssqltypes.UniqueIdentifier{},
 			PVarbinary:    []byte("zzz"),
 			PTinyint:      5,
 			PSmallint:     16000,
@@ -468,7 +470,7 @@ func TestTVP_WithTag(t *testing.T) {
 			PBinary:    []byte("ccc"),
 			PVarchar:   varcharNull,
 			PNvarchar:  nvarchar,
-			PID:        UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PID:        mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PVarbinary: bytesMock,
 			PTinyint:   i8,
 			PSmallint:  i16,
@@ -485,7 +487,7 @@ func TestTVP_WithTag(t *testing.T) {
 			PBinary:    []byte("www"),
 			PVarchar:   "eee",
 			PNvarchar:  "lll",
-			PID:        UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PID:        mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PVarbinary: []byte("zzz"),
 			PTinyint:   5,
 			PSmallint:  16000,
@@ -502,7 +504,7 @@ func TestTVP_WithTag(t *testing.T) {
 			PBinary:       nil,
 			PVarcharNull:  &varcharNull,
 			PNvarcharNull: &nvarchar,
-			PIDNull:       &UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PIDNull:       &mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PTinyintNull:  &i8,
 			PSmallintNull: &i16,
 			PIntNull:      &i32,
@@ -518,7 +520,7 @@ func TestTVP_WithTag(t *testing.T) {
 			PBinary:       []byte("www"),
 			PVarchar:      "eee",
 			PNvarchar:     "lll",
-			PIDNull:       &UniqueIdentifier{},
+			PIDNull:       &mssqltypes.UniqueIdentifier{},
 			PVarbinary:    []byte("zzz"),
 			PTinyint:      5,
 			PSmallint:     16000,
diff --git a/types.go b/types.go
index b6e7fb2b..6bf297f7 100644
--- a/types.go
+++ b/types.go
@@ -11,7 +11,8 @@ import (
 	"time"
 
 	"github.com/denisenkom/go-mssqldb/internal/cp"
-	"github.com/denisenkom/go-mssqldb/internal/decimal"
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
 // fixed-length data types
@@ -338,7 +339,7 @@ func readFixedType(ti *typeInfo, r *tdsBuffer) interface{} {
 	case typeInt8:
 		return int64(binary.LittleEndian.Uint64(buf))
 	default:
-		badStreamPanicf("Invalid typeid")
+		mssqlerror.BadStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -353,7 +354,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 	switch ti.TypeId {
 	case typeDateN:
 		if len(buf) != 3 {
-			badStreamPanicf("Invalid size for DATENTYPE")
+			mssqlerror.BadStreamPanicf("Invalid size for DATENTYPE")
 		}
 		return decodeDate(buf)
 	case typeTimeN:
@@ -375,13 +376,13 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return int64(binary.LittleEndian.Uint64(buf))
 		default:
-			badStreamPanicf("Invalid size for INTNTYPE: %d", len(buf))
+			mssqlerror.BadStreamPanicf("Invalid size for INTNTYPE: %d", len(buf))
 		}
 	case typeDecimal, typeNumeric, typeDecimalN, typeNumericN:
 		return decodeDecimal(ti.Prec, ti.Scale, buf)
 	case typeBitN:
 		if len(buf) != 1 {
-			badStreamPanicf("Invalid size for BITNTYPE")
+			mssqlerror.BadStreamPanicf("Invalid size for BITNTYPE")
 		}
 		return buf[0] != 0
 	case typeFltN:
@@ -391,7 +392,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return math.Float64frombits(binary.LittleEndian.Uint64(buf))
 		default:
-			badStreamPanicf("Invalid size for FLTNTYPE")
+			mssqlerror.BadStreamPanicf("Invalid size for FLTNTYPE")
 		}
 	case typeMoneyN:
 		switch len(buf) {
@@ -400,7 +401,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return decodeMoney(buf)
 		default:
-			badStreamPanicf("Invalid size for MONEYNTYPE")
+			mssqlerror.BadStreamPanicf("Invalid size for MONEYNTYPE")
 		}
 	case typeDateTim4:
 		return decodeDateTim4(buf)
@@ -413,7 +414,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return decodeDateTime(buf)
 		default:
-			badStreamPanicf("Invalid size for DATETIMENTYPE")
+			mssqlerror.BadStreamPanicf("Invalid size for DATETIMENTYPE")
 		}
 	case typeChar, typeVarChar:
 		return decodeChar(ti.Collation, buf)
@@ -425,7 +426,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		copy(cpy, buf)
 		return cpy
 	default:
-		badStreamPanicf("Invalid typeid")
+		mssqlerror.BadStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -464,7 +465,7 @@ func readShortLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 	case typeUdt:
 		return decodeUdt(*ti, buf)
 	default:
-		badStreamPanicf("Invalid typeid")
+		mssqlerror.BadStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -512,7 +513,7 @@ func readLongLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 	case typeNText:
 		return decodeNChar(buf)
 	default:
-		badStreamPanicf("Invalid typeid")
+		mssqlerror.BadStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -645,7 +646,7 @@ func readVariantType(ti *typeInfo, r *tdsBuffer) interface{} {
 		r.ReadFull(buf)
 		return decodeNChar(buf)
 	default:
-		badStreamPanicf("Invalid variant typeid")
+		mssqlerror.BadStreamPanicf("Invalid variant typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -671,7 +672,7 @@ func readPLPType(ti *typeInfo, r *tdsBuffer) interface{} {
 			break
 		}
 		if _, err := io.CopyN(buf, r, int64(chunksize)); err != nil {
-			badStreamPanicf("Reading PLP type failed: %s", err.Error())
+			mssqlerror.BadStreamPanicf("Reading PLP type failed: %s", err.Error())
 		}
 	}
 	switch ti.TypeId {
@@ -725,7 +726,7 @@ func readVarLen(ti *typeInfo, r *tdsBuffer) {
 		case 5, 6, 7:
 			ti.Size = 5
 		default:
-			badStreamPanicf("Invalid scale for TIME/DATETIME2/DATETIMEOFFSET type")
+			mssqlerror.BadStreamPanicf("Invalid scale for TIME/DATETIME2/DATETIMEOFFSET type")
 		}
 		switch ti.TypeId {
 		case typeDateTime2N:
@@ -805,7 +806,7 @@ func readVarLen(ti *typeInfo, r *tdsBuffer) {
 			ti.Reader = readVariantType
 		}
 	default:
-		badStreamPanicf("Invalid type %d", ti.TypeId)
+		mssqlerror.BadStreamPanicf("Invalid type %d", ti.TypeId)
 	}
 	return
 }
@@ -819,12 +820,12 @@ func decodeMoney(buf []byte) []byte {
 		uint64(buf[1])<<40 |
 		uint64(buf[2])<<48 |
 		uint64(buf[3])<<56)
-	return decimal.ScaleBytes(strconv.FormatInt(money, 10), 4)
+	return mssqltypes.ScaleBytes(strconv.FormatInt(money, 10), 4)
 }
 
 func decodeMoney4(buf []byte) []byte {
 	money := int32(binary.LittleEndian.Uint32(buf[0:4]))
-	return decimal.ScaleBytes(strconv.FormatInt(int64(money), 10), 4)
+	return mssqltypes.ScaleBytes(strconv.FormatInt(int64(money), 10), 4)
 }
 
 func decodeGuid(buf []byte) []byte {
@@ -836,7 +837,7 @@ func decodeGuid(buf []byte) []byte {
 func decodeDecimal(prec uint8, scale uint8, buf []byte) []byte {
 	var sign uint8
 	sign = buf[0]
-	var dec decimal.Decimal
+	var dec mssqltypes.Decimal
 	dec.SetPositive(sign != 0)
 	dec.SetPrec(prec)
 	dec.SetScale(scale)
@@ -994,7 +995,7 @@ func decodeChar(col cp.Collation, buf []byte) string {
 func decodeUcs2(buf []byte) string {
 	res, err := ucs22str(buf)
 	if err != nil {
-		badStreamPanicf("Invalid UCS2 encoding: %s", err.Error())
+		mssqlerror.BadStreamPanicf("Invalid UCS2 encoding: %s", err.Error())
 	}
 	return res
 }

From 95d9e8fd5071cfe6a88c86a4fb61deb7fd10fb79 Mon Sep 17 00:00:00 2001
From: v-kaywon <v-kaywon@microsoft.com>
Date: Wed, 11 Sep 2019 14:31:31 -0700
Subject: [PATCH 04/10] fix buf_test.go

---
 buf_test.go | 32 --------------------------------
 1 file changed, 32 deletions(-)

diff --git a/buf_test.go b/buf_test.go
index 76efbd1d..9d681665 100644
--- a/buf_test.go
+++ b/buf_test.go
@@ -282,35 +282,3 @@ func TestWrite_BufferBounds(t *testing.T) {
 		t.Fatal("FinishPacket failed:", err.Error())
 	}
 }
-
-func TestReadUsVarCharOrPanic(t *testing.T) {
-	memBuf := bytes.NewBuffer([]byte{3, 0, 0x31, 0, 0x32, 0, 0x33, 0})
-	s := readUsVarCharOrPanic(memBuf)
-	if s != "123" {
-		t.Errorf("UsVarChar expected to return 123 but it returned %s", s)
-	}
-
-	// test invalid usvarchar
-	defer func() {
-		recover()
-	}()
-	memBuf = bytes.NewBuffer([]byte{})
-	s = readUsVarCharOrPanic(memBuf)
-	t.Fatal("UsVarChar() should panic, but it didn't")
-}
-
-func TestReadBVarCharOrPanic(t *testing.T) {
-	memBuf := bytes.NewBuffer([]byte{3, 0x31, 0, 0x32, 0, 0x33, 0})
-	s := readBVarCharOrPanic(memBuf)
-	if s != "123" {
-		t.Errorf("readBVarCharOrPanic expected to return 123 but it returned %s", s)
-	}
-
-	// test invalid varchar
-	defer func() {
-		recover()
-	}()
-	memBuf = bytes.NewBuffer([]byte{})
-	s = readBVarCharOrPanic(memBuf)
-	t.Fatal("readBVarCharOrPanic() should panic on empty buffer, but it didn't")
-}

From 372f3d2d1ba241dfcf5ae80ef19771aba498fc9b Mon Sep 17 00:00:00 2001
From: Yuki Wong <v-kaywon@microsoft.com>
Date: Tue, 9 Jul 2019 16:59:04 -0700
Subject: [PATCH 05/10] Update issue templates

---
 .github/ISSUE_TEMPLATE/custom.md | 10 ++++++++++
 1 file changed, 10 insertions(+)
 create mode 100644 .github/ISSUE_TEMPLATE/custom.md

diff --git a/.github/ISSUE_TEMPLATE/custom.md b/.github/ISSUE_TEMPLATE/custom.md
new file mode 100644
index 00000000..48d5f81f
--- /dev/null
+++ b/.github/ISSUE_TEMPLATE/custom.md
@@ -0,0 +1,10 @@
+---
+name: Custom issue template
+about: Describe this issue template's purpose here.
+title: ''
+labels: ''
+assignees: ''
+
+---
+
+

From 83a323c964eeafa4d3318fef3d31265d4b18e7f3 Mon Sep 17 00:00:00 2001
From: Yuki Wong <v-kaywon@microsoft.com>
Date: Tue, 9 Jul 2019 17:04:05 -0700
Subject: [PATCH 06/10] Delete custom.md

---
 .github/ISSUE_TEMPLATE/custom.md | 10 ----------
 1 file changed, 10 deletions(-)
 delete mode 100644 .github/ISSUE_TEMPLATE/custom.md

diff --git a/.github/ISSUE_TEMPLATE/custom.md b/.github/ISSUE_TEMPLATE/custom.md
deleted file mode 100644
index 48d5f81f..00000000
--- a/.github/ISSUE_TEMPLATE/custom.md
+++ /dev/null
@@ -1,10 +0,0 @@
----
-name: Custom issue template
-about: Describe this issue template's purpose here.
-title: ''
-labels: ''
-assignees: ''
-
----
-
-

From 2b0a628ab0e1d4a185ae822a91b4303964b114cb Mon Sep 17 00:00:00 2001
From: v-kaywon <v-kaywon@microsoft.com>
Date: Wed, 11 Sep 2019 14:29:29 -0700
Subject: [PATCH 07/10] sub package out mssql specific types

---
 buf.go                                        |  20 +-
 bulkcopy.go                                   |  20 +-
 datetimeoffset_example_test.go                |  10 +-
 error.go => internal/mssqlerror/error.go      |  17 +-
 internal/{decimal => mssqltypes}/decimal.go   |   2 +-
 .../{decimal => mssqltypes}/decimal_test.go   |   2 +-
 internal/mssqltypes/mssqltypes.go             |  20 ++
 .../mssqltypes/uniqueidentifier.go            |   6 +-
 .../mssqltypes/uniqueidentifier_test.go       |   2 +-
 mssql.go                                      |   3 +-
 mssql_go19.go                                 |  33 ++--
 queries_go110_test.go                         |  15 +-
 queries_go19_test.go                          |  25 +--
 queries_test.go                               |  13 +-
 token.go                                      | 110 +++++------
 tvp_go19_db_test.go                           | 174 +++++++++---------
 types.go                                      |  39 ++--
 17 files changed, 280 insertions(+), 231 deletions(-)
 rename error.go => internal/mssqlerror/error.go (64%)
 rename internal/{decimal => mssqltypes}/decimal.go (99%)
 rename internal/{decimal => mssqltypes}/decimal_test.go (99%)
 create mode 100644 internal/mssqltypes/mssqltypes.go
 rename uniqueidentifier.go => internal/mssqltypes/uniqueidentifier.go (85%)
 rename uniqueidentifier_test.go => internal/mssqltypes/uniqueidentifier_test.go (98%)

diff --git a/buf.go b/buf.go
index ba39b40f..56e56dda 100644
--- a/buf.go
+++ b/buf.go
@@ -4,6 +4,8 @@ import (
 	"encoding/binary"
 	"errors"
 	"io"
+
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 )
 
 type packetType uint8
@@ -186,7 +188,7 @@ func (r *tdsBuffer) ReadByte() (res byte, err error) {
 func (r *tdsBuffer) byte() byte {
 	b, err := r.ReadByte()
 	if err != nil {
-		badStreamPanic(err)
+		mssqlerror.BadStreamPanic(err)
 	}
 	return b
 }
@@ -194,7 +196,7 @@ func (r *tdsBuffer) byte() byte {
 func (r *tdsBuffer) ReadFull(buf []byte) {
 	_, err := io.ReadFull(r, buf[:])
 	if err != nil {
-		badStreamPanic(err)
+		mssqlerror.BadStreamPanic(err)
 	}
 }
 
@@ -227,7 +229,7 @@ func (r *tdsBuffer) BVarChar() string {
 func readBVarCharOrPanic(r io.Reader) string {
 	s, err := readBVarChar(r)
 	if err != nil {
-		badStreamPanic(err)
+		mssqlerror.BadStreamPanic(err)
 	}
 	return s
 }
@@ -235,7 +237,7 @@ func readBVarCharOrPanic(r io.Reader) string {
 func readUsVarCharOrPanic(r io.Reader) string {
 	s, err := readUsVarChar(r)
 	if err != nil {
-		badStreamPanic(err)
+		mssqlerror.BadStreamPanic(err)
 	}
 	return s
 }
@@ -244,6 +246,16 @@ func (r *tdsBuffer) UsVarChar() string {
 	return readUsVarCharOrPanic(r)
 }
 
+func (r *tdsBuffer) readUcs2(numchars int) string {
+	b := make([]byte, numchars*2)
+	r.ReadFull(b)
+	res, err := ucs22str(b)
+	if err != nil {
+		mssqlerror.BadStreamPanic(err)
+	}
+	return res
+}
+
 func (r *tdsBuffer) Read(buf []byte) (copied int, err error) {
 	copied = 0
 	err = nil
diff --git a/bulkcopy.go b/bulkcopy.go
index 1d5eacb3..1792d275 100644
--- a/bulkcopy.go
+++ b/bulkcopy.go
@@ -10,7 +10,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/denisenkom/go-mssqldb/internal/decimal"
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
 type Bulk struct {
@@ -490,24 +490,24 @@ func (b *Bulk) makeParam(val DataValue, col columnStruct) (res param, err error)
 	case typeDecimal, typeDecimalN, typeNumeric, typeNumericN:
 		prec := col.ti.Prec
 		scale := col.ti.Scale
-		var dec decimal.Decimal
+		var dec mssqltypes.Decimal
 		switch v := val.(type) {
 		case int:
-			dec = decimal.Int64ToDecimalScale(int64(v), 0)
+			dec = mssqltypes.Int64ToDecimalScale(int64(v), 0)
 		case int8:
-			dec = decimal.Int64ToDecimalScale(int64(v), 0)
+			dec = mssqltypes.Int64ToDecimalScale(int64(v), 0)
 		case int16:
-			dec = decimal.Int64ToDecimalScale(int64(v), 0)
+			dec = mssqltypes.Int64ToDecimalScale(int64(v), 0)
 		case int32:
-			dec = decimal.Int64ToDecimalScale(int64(v), 0)
+			dec = mssqltypes.Int64ToDecimalScale(int64(v), 0)
 		case int64:
-			dec = decimal.Int64ToDecimalScale(int64(v), 0)
+			dec = mssqltypes.Int64ToDecimalScale(int64(v), 0)
 		case float32:
-			dec, err = decimal.Float64ToDecimalScale(float64(v), scale)
+			dec, err = mssqltypes.Float64ToDecimalScale(float64(v), scale)
 		case float64:
-			dec, err = decimal.Float64ToDecimalScale(float64(v), scale)
+			dec, err = mssqltypes.Float64ToDecimalScale(float64(v), scale)
 		case string:
-			dec, err = decimal.StringToDecimalScale(v, scale)
+			dec, err = mssqltypes.StringToDecimalScale(v, scale)
 		default:
 			return res, fmt.Errorf("unknown value for decimal: %T %#v", v, v)
 		}
diff --git a/datetimeoffset_example_test.go b/datetimeoffset_example_test.go
index 186f8196..95a0de03 100644
--- a/datetimeoffset_example_test.go
+++ b/datetimeoffset_example_test.go
@@ -9,8 +9,8 @@ import (
 	"log"
 	"time"
 
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 	"github.com/golang-sql/civil"
-	"github.com/denisenkom/go-mssqldb"
 )
 
 // This example shows how to insert and retrieve date and time types data
@@ -56,9 +56,9 @@ func insertDateTime(db *sql.DB) {
 	var timeCol civil.Time = civil.TimeOf(tin)
 	var dateCol civil.Date = civil.DateOf(tin)
 	var smalldatetimeCol string = "2006-01-02 22:04:00"
-	var datetimeCol mssql.DateTime1 = mssql.DateTime1(tin)
+	var datetimeCol mssqltypes.DateTime1 = mssqltypes.DateTime1(tin)
 	var datetime2Col civil.DateTime = civil.DateTimeOf(tin)
-	var datetimeoffsetCol mssql.DateTimeOffset = mssql.DateTimeOffset(tin)
+	var datetimeoffsetCol mssqltypes.DateTimeOffset = mssqltypes.DateTimeOffset(tin)
 	_, err = stmt.Exec(timeCol, dateCol, smalldatetimeCol, datetimeCol, datetime2Col, datetimeoffsetCol)
 	if err != nil {
 		log.Fatal(err)
@@ -103,8 +103,8 @@ func retrieveDateTimeOutParam(db *sql.DB) {
 		log.Fatal(err)
 	}
 	var (
-		timeOutParam, datetime2OutParam, datetimeoffsetOutParam mssql.DateTimeOffset
-		dateOutParam, datetimeOutParam                          mssql.DateTime1
+		timeOutParam, datetime2OutParam, datetimeoffsetOutParam mssqltypes.DateTimeOffset
+		dateOutParam, datetimeOutParam                          mssqltypes.DateTime1
 		smalldatetimeOutParam                                   string
 	)
 	_, err = db.Exec("OutDatetimeProc",
diff --git a/error.go b/internal/mssqlerror/error.go
similarity index 64%
rename from error.go
rename to internal/mssqlerror/error.go
index 2e5bacee..fe4ce619 100644
--- a/error.go
+++ b/internal/mssqlerror/error.go
@@ -1,4 +1,4 @@
-package mssql
+package mssqlerror
 
 import (
 	"fmt"
@@ -19,6 +19,7 @@ type Error struct {
 	LineNo     int32
 }
 
+// Error returns the SQL Server error message.
 func (e Error) Error() string {
 	return "mssql: " + e.Message
 }
@@ -28,34 +29,42 @@ func (e Error) SQLErrorNumber() int32 {
 	return e.Number
 }
 
+// SQLErrorState returns the SQL Server error state.
 func (e Error) SQLErrorState() uint8 {
 	return e.State
 }
 
+// SQLErrorClass returns the SQL Server error class.
 func (e Error) SQLErrorClass() uint8 {
 	return e.Class
 }
 
+// SQLErrorMessage returns the SQL Server error message.
 func (e Error) SQLErrorMessage() string {
 	return e.Message
 }
 
+// SQLErrorServerName returns the SQL Server name.
 func (e Error) SQLErrorServerName() string {
 	return e.ServerName
 }
 
+// SQLErrorProcName returns the procedure name.
 func (e Error) SQLErrorProcName() string {
 	return e.ProcName
 }
 
+// SQLErrorLineNo returns the error line number.
 func (e Error) SQLErrorLineNo() int32 {
 	return e.LineNo
 }
 
+// StreamError represents TDS stream error.
 type StreamError struct {
 	Message string
 }
 
+// Error returns the TDS stream error message.
 func (e StreamError) Error() string {
 	return e.Message
 }
@@ -64,10 +73,12 @@ func streamErrorf(format string, v ...interface{}) StreamError {
 	return StreamError{"Invalid TDS stream: " + fmt.Sprintf(format, v...)}
 }
 
-func badStreamPanic(err error) {
+// BadStreamPanic calls panic with err.
+func BadStreamPanic(err error) {
 	panic(err)
 }
 
-func badStreamPanicf(format string, v ...interface{}) {
+// BadStreamPanicf calls panic with a formatted error message as an invalid TDS stream error.
+func BadStreamPanicf(format string, v ...interface{}) {
 	panic(streamErrorf(format, v...))
 }
diff --git a/internal/decimal/decimal.go b/internal/mssqltypes/decimal.go
similarity index 99%
rename from internal/decimal/decimal.go
rename to internal/mssqltypes/decimal.go
index 7da0375d..6f4e7b2a 100644
--- a/internal/decimal/decimal.go
+++ b/internal/mssqltypes/decimal.go
@@ -1,4 +1,4 @@
-package decimal
+package mssqltypes
 
 import (
 	"encoding/binary"
diff --git a/internal/decimal/decimal_test.go b/internal/mssqltypes/decimal_test.go
similarity index 99%
rename from internal/decimal/decimal_test.go
rename to internal/mssqltypes/decimal_test.go
index 4086a964..f75cf79e 100644
--- a/internal/decimal/decimal_test.go
+++ b/internal/mssqltypes/decimal_test.go
@@ -1,4 +1,4 @@
-package decimal
+package mssqltypes
 
 import (
 	"math"
diff --git a/internal/mssqltypes/mssqltypes.go b/internal/mssqltypes/mssqltypes.go
new file mode 100644
index 00000000..92b04b3c
--- /dev/null
+++ b/internal/mssqltypes/mssqltypes.go
@@ -0,0 +1,20 @@
+// +build go1.9
+
+package mssqltypes
+
+import "time"
+
+// VarChar parameter types.
+type VarChar string
+
+// NVarCharMax encodes parameters to NVarChar(max) SQL type.
+type NVarCharMax string
+
+// VarCharMax encodes parameter to VarChar(max) SQL type.
+type VarCharMax string
+
+// DateTime1 encodes parameters to original DateTime SQL types.
+type DateTime1 time.Time
+
+// DateTimeOffset encodes parameters to DateTimeOffset, preserving the UTC offset.
+type DateTimeOffset time.Time
diff --git a/uniqueidentifier.go b/internal/mssqltypes/uniqueidentifier.go
similarity index 85%
rename from uniqueidentifier.go
rename to internal/mssqltypes/uniqueidentifier.go
index c8ef3149..39a28ead 100644
--- a/uniqueidentifier.go
+++ b/internal/mssqltypes/uniqueidentifier.go
@@ -1,4 +1,4 @@
-package mssql
+package mssqltypes
 
 import (
 	"database/sql/driver"
@@ -7,8 +7,10 @@ import (
 	"fmt"
 )
 
+// UniqueIdentifier encodes parameters to Uniqueidentifier SQL type.
 type UniqueIdentifier [16]byte
 
+// Scan converts v to UniqueIdentifier
 func (u *UniqueIdentifier) Scan(v interface{}) error {
 	reverse := func(b []byte) {
 		for i, j := 0, len(b)-1; i < j; i, j = i+1, j-1 {
@@ -52,6 +54,7 @@ func (u *UniqueIdentifier) Scan(v interface{}) error {
 	}
 }
 
+// Value converts UniqueIdentifier to bytes
 func (u UniqueIdentifier) Value() (driver.Value, error) {
 	reverse := func(b []byte) {
 		for i, j := 0, len(b)-1; i < j; i, j = i+1, j-1 {
@@ -69,6 +72,7 @@ func (u UniqueIdentifier) Value() (driver.Value, error) {
 	return raw, nil
 }
 
+// String converts UniqueIdentifier to string
 func (u UniqueIdentifier) String() string {
 	return fmt.Sprintf("%X-%X-%X-%X-%X", u[0:4], u[4:6], u[6:8], u[8:10], u[10:])
 }
diff --git a/uniqueidentifier_test.go b/internal/mssqltypes/uniqueidentifier_test.go
similarity index 98%
rename from uniqueidentifier_test.go
rename to internal/mssqltypes/uniqueidentifier_test.go
index 2a29133a..22249614 100644
--- a/uniqueidentifier_test.go
+++ b/internal/mssqltypes/uniqueidentifier_test.go
@@ -1,4 +1,4 @@
-package mssql
+package mssqltypes
 
 import (
 	"bytes"
diff --git a/mssql.go b/mssql.go
index e37109cd..2949163d 100644
--- a/mssql.go
+++ b/mssql.go
@@ -15,6 +15,7 @@ import (
 	"time"
 	"unicode"
 
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 	"github.com/denisenkom/go-mssqldb/internal/querytext"
 )
 
@@ -188,7 +189,7 @@ func (c *Conn) checkBadConn(err error) error {
 	case net.Error:
 		c.connectionGood = false
 		return err
-	case StreamError:
+	case mssqlerror.StreamError:
 		c.connectionGood = false
 		return err
 	default:
diff --git a/mssql_go19.go b/mssql_go19.go
index a2bd1167..170a2a0d 100644
--- a/mssql_go19.go
+++ b/mssql_go19.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	// "github.com/cockroachdb/apd"
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 	"github.com/golang-sql/civil"
 )
 
@@ -26,29 +27,17 @@ type MssqlStmt = Stmt               // Deprecated: users should transition to th
 
 var _ driver.NamedValueChecker = &Conn{}
 
-// VarChar parameter types.
-type VarChar string
-
-type NVarCharMax string
-type VarCharMax string
-
-// DateTime1 encodes parameters to original DateTime SQL types.
-type DateTime1 time.Time
-
-// DateTimeOffset encodes parameters to DateTimeOffset, preserving the UTC offset.
-type DateTimeOffset time.Time
-
 func convertInputParameter(val interface{}) (interface{}, error) {
 	switch v := val.(type) {
-	case VarChar:
+	case mssqltypes.VarChar:
 		return val, nil
-	case NVarCharMax:
+	case mssqltypes.NVarCharMax:
 		return val, nil
-	case VarCharMax:
+	case mssqltypes.VarCharMax:
 		return val, nil
-	case DateTime1:
+	case mssqltypes.DateTime1:
 		return val, nil
-	case DateTimeOffset:
+	case mssqltypes.DateTimeOffset:
 		return val, nil
 	case civil.Date:
 		return val, nil
@@ -123,24 +112,24 @@ func (c *Conn) CheckNamedValue(nv *driver.NamedValue) error {
 
 func (s *Stmt) makeParamExtra(val driver.Value) (res param, err error) {
 	switch val := val.(type) {
-	case VarChar:
+	case mssqltypes.VarChar:
 		res.ti.TypeId = typeBigVarChar
 		res.buffer = []byte(val)
 		res.ti.Size = len(res.buffer)
-	case VarCharMax:
+	case mssqltypes.VarCharMax:
 		res.ti.TypeId = typeBigVarChar
 		res.buffer = []byte(val)
 		res.ti.Size = 0 // currently zero forces varchar(max)
-	case NVarCharMax:
+	case mssqltypes.NVarCharMax:
 		res.ti.TypeId = typeNVarChar
 		res.buffer = str2ucs2(string(val))
 		res.ti.Size = 0 // currently zero forces nvarchar(max)
-	case DateTime1:
+	case mssqltypes.DateTime1:
 		t := time.Time(val)
 		res.ti.TypeId = typeDateTimeN
 		res.buffer = encodeDateTime(t)
 		res.ti.Size = len(res.buffer)
-	case DateTimeOffset:
+	case mssqltypes.DateTimeOffset:
 		res.ti.TypeId = typeDateTimeOffsetN
 		res.ti.Scale = 7
 		res.buffer = encodeDateTimeOffset(time.Time(val), int(res.ti.Scale))
diff --git a/queries_go110_test.go b/queries_go110_test.go
index debb636f..f7e7b16e 100644
--- a/queries_go110_test.go
+++ b/queries_go110_test.go
@@ -9,6 +9,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 	"github.com/golang-sql/civil"
 )
 
@@ -80,14 +81,14 @@ select
 ;
 	`,
 		sql.Named("nv", "base type nvarchar"),
-		sql.Named("v", VarChar("base type varchar")),
-		sql.Named("nvcm", NVarCharMax(strings.Repeat("x", 5000))),
-		sql.Named("vcm", VarCharMax(strings.Repeat("x", 5000))),
-		sql.Named("dt1", DateTime1(tin)),
+		sql.Named("v", mssqltypes.VarChar("base type varchar")),
+		sql.Named("nvcm", mssqltypes.NVarCharMax(strings.Repeat("x", 5000))),
+		sql.Named("vcm", mssqltypes.VarCharMax(strings.Repeat("x", 5000))),
+		sql.Named("dt1", mssqltypes.DateTime1(tin)),
 		sql.Named("dt2", civil.DateTimeOf(tin)),
 		sql.Named("d", civil.DateOf(tin)),
 		sql.Named("tm", civil.TimeOf(tin)),
-		sql.Named("dto", DateTimeOffset(tin)),
+		sql.Named("dto", mssqltypes.DateTimeOffset(tin)),
 	)
 	err = row.Scan(&nv, &v, &nvcm, &vcm, &dt1, &dt2, &d, &tm, &dto)
 	if err != nil {
@@ -153,11 +154,11 @@ select
 		sql.Named("nv", sin),
 		sql.Named("v", sin),
 		sql.Named("tgo", tin),
-		sql.Named("dt1", DateTime1(tin)),
+		sql.Named("dt1", mssqltypes.DateTime1(tin)),
 		sql.Named("dt2", civil.DateTimeOf(tin)),
 		sql.Named("d", civil.DateOf(tin)),
 		sql.Named("tm", civil.TimeOf(tin)),
-		sql.Named("dto", DateTimeOffset(tin)),
+		sql.Named("dto", mssqltypes.DateTimeOffset(tin)),
 	).Scan(&nv, &v, &tgo, &dt1, &dt2, &d, &tm, &dto)
 	if err != nil {
 		t.Fatal(err)
diff --git a/queries_go19_test.go b/queries_go19_test.go
index e3addd03..5e86818d 100644
--- a/queries_go19_test.go
+++ b/queries_go19_test.go
@@ -10,6 +10,9 @@ import (
 	"regexp"
 	"testing"
 	"time"
+
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
 func TestOutputParam(t *testing.T) {
@@ -174,8 +177,8 @@ END;
 			if err != nil {
 				t.Fatal(err)
 			}
-			var datetime_param DateTime1
-			datetime_param = DateTime1(tin)
+			var datetime_param mssqltypes.DateTime1
+			datetime_param = mssqltypes.DateTime1(tin)
 			_, err = db.ExecContext(ctx, sqltextrun,
 				sql.Named("datetime", sql.Out{Dest: &datetime_param}),
 			)
@@ -224,7 +227,7 @@ END;
 
 		t.Run("should fail if destination has invalid type", func(t *testing.T) {
 			// Error type should not be supported
-			var err_out Error
+			var err_out mssqlerror.Error
 			_, err := db.ExecContext(ctx, sqltextrun,
 				sql.Named("bid", sql.Out{Dest: &err_out}),
 			)
@@ -244,7 +247,7 @@ END;
 
 		t.Run("should fail if parameter has invalid type", func(t *testing.T) {
 			// passing invalid parameter type
-			var err_val Error
+			var err_val mssqlerror.Error
 			_, err = db.ExecContext(ctx, sqltextrun, err_val)
 			if err == nil {
 				t.Error("Expected to fail but it didn't")
@@ -346,7 +349,7 @@ END;
 	t.Run("original test", func(t *testing.T) {
 		var bout int64 = 3
 		var cout string
-		var vout VarChar
+		var vout mssqltypes.VarChar
 		_, err = db.ExecContext(ctx, sqltextrun,
 			sql.Named("aid", 5),
 			sql.Named("bid", sql.Out{Dest: &bout}),
@@ -964,12 +967,12 @@ func TestDateTimeParam19(t *testing.T) {
 	var emptydate time.Time
 	mindate1 := time.Date(1753, 1, 1, 0, 0, 0, 0, time.UTC)
 	maxdate1 := time.Date(9999, 12, 31, 23, 59, 59, 997000000, time.UTC)
-	testdates1 := []DateTime1{
-		DateTime1(mindate1),
-		DateTime1(maxdate1),
-		DateTime1(time.Date(1752, 12, 31, 23, 59, 59, 997000000, time.UTC)), // just a little below minimum date
-		DateTime1(time.Date(10000, 1, 1, 0, 0, 0, 0, time.UTC)),             // just a little over maximum date
-		DateTime1(emptydate),
+	testdates1 := []mssqltypes.DateTime1{
+		mssqltypes.DateTime1(mindate1),
+		mssqltypes.DateTime1(maxdate1),
+		mssqltypes.DateTime1(time.Date(1752, 12, 31, 23, 59, 59, 997000000, time.UTC)), // just a little below minimum date
+		mssqltypes.DateTime1(time.Date(10000, 1, 1, 0, 0, 0, 0, time.UTC)),             // just a little over maximum date
+		mssqltypes.DateTime1(emptydate),
 	}
 
 	for _, test := range testdates1 {
diff --git a/queries_test.go b/queries_test.go
index 2b476a84..1098899a 100644
--- a/queries_test.go
+++ b/queries_test.go
@@ -14,6 +14,9 @@ import (
 	"sync"
 	"testing"
 	"time"
+
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
 func driverWithProcess(t *testing.T) *Driver {
@@ -619,7 +622,7 @@ func TestError(t *testing.T) {
 		t.Fatal("Query should fail")
 	}
 
-	if sqlerr, ok := err.(Error); !ok {
+	if sqlerr, ok := err.(mssqlerror.Error); !ok {
 		t.Fatalf("Should be sql error, actually %T, %v", err, err)
 	} else {
 		if sqlerr.Number != 2812 { // Could not find stored procedure 'bad'
@@ -836,7 +839,7 @@ func TestUniqueIdentifierParam(t *testing.T) {
 		uuid interface{}
 	}
 
-	expected := UniqueIdentifier{0x01, 0x23, 0x45, 0x67,
+	expected := mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67,
 		0x89, 0xAB,
 		0xCD, 0xEF,
 		0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF,
@@ -856,7 +859,7 @@ func TestUniqueIdentifierParam(t *testing.T) {
 
 	for _, test := range values {
 		t.Run(test.name, func(t *testing.T) {
-			var uuid2 UniqueIdentifier
+			var uuid2 mssqltypes.UniqueIdentifier
 			err := conn.QueryRow("select ?", test.uuid).Scan(&uuid2)
 			if err != nil {
 				t.Fatal("select / scan failed", err.Error())
@@ -969,7 +972,7 @@ func TestErrorInfo(t *testing.T) {
 	defer conn.Close()
 
 	_, err := conn.Exec("select bad")
-	if sqlError, ok := err.(Error); ok {
+	if sqlError, ok := err.(mssqlerror.Error); ok {
 		if sqlError.SQLErrorNumber() != 207 /*invalid column name*/ {
 			t.Errorf("Query failed with unexpected error number %d %s", sqlError.SQLErrorNumber(), sqlError.SQLErrorMessage())
 		}
@@ -980,7 +983,7 @@ func TestErrorInfo(t *testing.T) {
 		t.Error("Failed to convert error to SQLErorr", err)
 	}
 	_, err = conn.Exec("RAISERROR('test message', 18, 111)")
-	if sqlError, ok := err.(Error); ok {
+	if sqlError, ok := err.(mssqlerror.Error); ok {
 		if sqlError.SQLErrorNumber() != 50000 {
 			t.Errorf("Query failed with unexpected error number %d %s", sqlError.SQLErrorNumber(), sqlError.SQLErrorMessage())
 		}
diff --git a/token.go b/token.go
index 1acac8a5..7b4bd4f0 100644
--- a/token.go
+++ b/token.go
@@ -9,6 +9,8 @@ import (
 	"net"
 	"strconv"
 	"strings"
+
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 )
 
 //go:generate stringer -type token
@@ -87,18 +89,18 @@ type doneStruct struct {
 	Status   uint16
 	CurCmd   uint16
 	RowCount uint64
-	errors   []Error
+	errors   []mssqlerror.Error
 }
 
 func (d doneStruct) isError() bool {
 	return d.Status&doneError != 0 || len(d.errors) > 0
 }
 
-func (d doneStruct) getError() Error {
+func (d doneStruct) getError() mssqlerror.Error {
 	if len(d.errors) > 0 {
 		return d.errors[len(d.errors)-1]
 	} else {
-		return Error{Message: "Request failed but didn't provide reason"}
+		return mssqlerror.Error{Message: "Request failed but didn't provide reason"}
 	}
 }
 
@@ -137,127 +139,127 @@ func processEnvChg(sess *tdsSession) {
 			return
 		}
 		if err != nil {
-			badStreamPanic(err)
+			mssqlerror.BadStreamPanic(err)
 		}
 		switch envtype {
 		case envTypDatabase:
 			sess.database, err = readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			_, err = readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTypLanguage:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTypCharset:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTypPacketSize:
 			packetsize, err := readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			_, err = readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			packetsizei, err := strconv.Atoi(packetsize)
 			if err != nil {
-				badStreamPanicf("Invalid Packet size value returned from server (%s): %s", packetsize, err.Error())
+				mssqlerror.BadStreamPanicf("Invalid Packet size value returned from server (%s): %s", packetsize, err.Error())
 			}
 			sess.buf.ResizeBuffer(packetsizei)
 		case envSortId:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envSortFlags:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envSqlCollation:
 			// currently ignored
 			var collationSize uint8
 			err = binary.Read(r, binary.LittleEndian, &collationSize)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 
 			// SQL Collation data should contain 5 bytes in length
 			if collationSize != 5 {
-				badStreamPanicf("Invalid SQL Collation size value returned from server: %d", collationSize)
+				mssqlerror.BadStreamPanicf("Invalid SQL Collation size value returned from server: %d", collationSize)
 			}
 
 			// 4 bytes, contains: LCID ColFlags Version
 			var info uint32
 			err = binary.Read(r, binary.LittleEndian, &info)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 
 			// 1 byte, contains: sortID
 			var sortID uint8
 			err = binary.Read(r, binary.LittleEndian, &sortID)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTypBeginTran:
 			tranid, err := readBVarByte(r)
 			if len(tranid) != 8 {
-				badStreamPanicf("invalid size of transaction identifier: %d", len(tranid))
+				mssqlerror.BadStreamPanicf("invalid size of transaction identifier: %d", len(tranid))
 			}
 			sess.tranid = binary.LittleEndian.Uint64(tranid)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			if sess.logFlags&logTransaction != 0 {
 				sess.log.Printf("BEGIN TRANSACTION %x\n", sess.tranid)
 			}
 			_, err = readBVarByte(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTypCommitTran, envTypRollbackTran:
 			_, err = readBVarByte(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			_, err = readBVarByte(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			if sess.logFlags&logTransaction != 0 {
 				if envtype == envTypCommitTran {
@@ -271,81 +273,81 @@ func processEnvChg(sess *tdsSession) {
 			// currently ignored
 			// new value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envDefectTran:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envDatabaseMirrorPartner:
 			sess.partner, err = readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			_, err = readBVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envPromoteTran:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// dtc token
 			// spec says it should be L_VARBYTE, so this code might be wrong
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTranMgrAddr:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// XACT_MANAGER_ADDRESS = B_VARBYTE
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envTranEnded:
 			// currently ignored
 			// old value, B_VARBYTE
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envResetConnAck:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envStartedInstanceName:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// instance name
 			if _, err = readBVarChar(r); err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 		case envRouting:
 			// RoutingData message is:
@@ -355,24 +357,24 @@ func processEnvChg(sess *tdsSession) {
 			// AlternateServer             US_VARCHAR
 			_, err := readUshort(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			protocol, err := readByte(r)
 			if err != nil || protocol != 0 {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			newPort, err := readUshort(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			newServer, err := readUsVarChar(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			// consume the OLDVALUE = %x00 %x00
 			_, err = readUshort(r)
 			if err != nil {
-				badStreamPanic(err)
+				mssqlerror.BadStreamPanic(err)
 			}
 			sess.routedServer = newServer
 			sess.routedPort = newPort
@@ -441,7 +443,7 @@ func parseLoginAck(r *tdsBuffer) loginAckStruct {
 	prognamelen := buf[1+4]
 	var err error
 	if res.ProgName, err = ucs22str(buf[1+4+1 : 1+4+1+prognamelen*2]); err != nil {
-		badStreamPanic(err)
+		mssqlerror.BadStreamPanic(err)
 	}
 	res.ProgVer = binary.BigEndian.Uint32(buf[size-4:])
 	return res
@@ -489,7 +491,7 @@ func parseNbcRow(r *tdsBuffer, columns []columnStruct, row []interface{}) {
 }
 
 // http://msdn.microsoft.com/en-us/library/dd304156.aspx
-func parseError72(r *tdsBuffer) (res Error) {
+func parseError72(r *tdsBuffer) (res mssqlerror.Error) {
 	length := r.uint16()
 	_ = length // ignore length
 	res.Number = r.int32()
@@ -503,7 +505,7 @@ func parseError72(r *tdsBuffer) (res Error) {
 }
 
 // http://msdn.microsoft.com/en-us/library/dd304156.aspx
-func parseInfo(r *tdsBuffer) (res Error) {
+func parseInfo(r *tdsBuffer) (res mssqlerror.Error) {
 	length := r.uint16()
 	_ = length // ignore length
 	res.Number = r.int32()
@@ -558,10 +560,10 @@ func processSingleResponse(sess *tdsSession, ch chan tokenStruct, outs map[strin
 		return
 	}
 	if packet_type != packReply {
-		badStreamPanic(fmt.Errorf("unexpected packet type in reply: got %v, expected %v", packet_type, packReply))
+		mssqlerror.BadStreamPanic(fmt.Errorf("unexpected packet type in reply: got %v, expected %v", packet_type, packReply))
 	}
 	var columns []columnStruct
-	errs := make([]Error, 0, 5)
+	errs := make([]mssqlerror.Error, 0, 5)
 	for {
 		token := token(sess.buf.byte())
 		if sess.logFlags&logDebug != 0 {
@@ -646,7 +648,7 @@ func processSingleResponse(sess *tdsSession, ch chan tokenStruct, outs map[strin
 				}
 			}
 		default:
-			badStreamPanic(fmt.Errorf("unknown token type returned: %v", token))
+			mssqlerror.BadStreamPanic(fmt.Errorf("unknown token type returned: %v", token))
 		}
 	}
 }
diff --git a/tvp_go19_db_test.go b/tvp_go19_db_test.go
index 6cf42641..d5f33db0 100644
--- a/tvp_go19_db_test.go
+++ b/tvp_go19_db_test.go
@@ -9,6 +9,8 @@ import (
 	"reflect"
 	"testing"
 	"time"
+
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
 const (
@@ -40,87 +42,87 @@ const (
 )
 
 type TvptableRow struct {
-	PBinary       []byte            `db:"p_binary"`
-	PVarchar      string            `db:"p_varchar"`
-	PVarcharNull  *string           `db:"p_varcharNull"`
-	PNvarchar     string            `db:"p_nvarchar"`
-	PNvarcharNull *string           `db:"p_nvarcharNull"`
-	PID           UniqueIdentifier  `db:"p_id"`
-	PIDNull       *UniqueIdentifier `db:"p_idNull"`
-	PVarbinary    []byte            `db:"p_varbinary"`
-	PTinyint      int8              `db:"p_tinyint"`
-	PTinyintNull  *int8             `db:"p_tinyintNull"`
-	PSmallint     int16             `db:"p_smallint"`
-	PSmallintNull *int16            `db:"p_smallintNull"`
-	PInt          int32             `db:"p_int"`
-	PIntNull      *int32            `db:"p_intNull"`
-	PBigint       int64             `db:"p_bigint"`
-	PBigintNull   *int64            `db:"p_bigintNull"`
-	PBit          bool              `db:"p_bit"`
-	PBitNull      *bool             `db:"p_bitNull"`
-	PFloat32      float32           `db:"p_float32"`
-	PFloatNull32  *float32          `db:"p_floatNull32"`
-	PFloat64      float64           `db:"p_float64"`
-	PFloatNull64  *float64          `db:"p_floatNull64"`
-	DTime         time.Time         `db:"p_timeNull"`
-	DTimeNull     *time.Time        `db:"p_time"`
-	Pint          int               `db:"pInt"`
-	PintNull      *int              `db:"pIntNull"`
+	PBinary       []byte                       `db:"p_binary"`
+	PVarchar      string                       `db:"p_varchar"`
+	PVarcharNull  *string                      `db:"p_varcharNull"`
+	PNvarchar     string                       `db:"p_nvarchar"`
+	PNvarcharNull *string                      `db:"p_nvarcharNull"`
+	PID           mssqltypes.UniqueIdentifier  `db:"p_id"`
+	PIDNull       *mssqltypes.UniqueIdentifier `db:"p_idNull"`
+	PVarbinary    []byte                       `db:"p_varbinary"`
+	PTinyint      int8                         `db:"p_tinyint"`
+	PTinyintNull  *int8                        `db:"p_tinyintNull"`
+	PSmallint     int16                        `db:"p_smallint"`
+	PSmallintNull *int16                       `db:"p_smallintNull"`
+	PInt          int32                        `db:"p_int"`
+	PIntNull      *int32                       `db:"p_intNull"`
+	PBigint       int64                        `db:"p_bigint"`
+	PBigintNull   *int64                       `db:"p_bigintNull"`
+	PBit          bool                         `db:"p_bit"`
+	PBitNull      *bool                        `db:"p_bitNull"`
+	PFloat32      float32                      `db:"p_float32"`
+	PFloatNull32  *float32                     `db:"p_floatNull32"`
+	PFloat64      float64                      `db:"p_float64"`
+	PFloatNull64  *float64                     `db:"p_floatNull64"`
+	DTime         time.Time                    `db:"p_timeNull"`
+	DTimeNull     *time.Time                   `db:"p_time"`
+	Pint          int                          `db:"pInt"`
+	PintNull      *int                         `db:"pIntNull"`
 }
 
 type TvptableRowWithSkipTag struct {
-	PBinary           []byte            `db:"p_binary"`
-	SkipPBinary       []byte            `json:"-"`
-	PVarchar          string            `db:"p_varchar"`
-	SkipPVarchar      string            `tvp:"-"`
-	PVarcharNull      *string           `db:"p_varcharNull"`
-	SkipPVarcharNull  *string           `json:"-" tvp:"-"`
-	PNvarchar         string            `db:"p_nvarchar"`
-	SkipPNvarchar     string            `json:"-"`
-	PNvarcharNull     *string           `db:"p_nvarcharNull"`
-	SkipPNvarcharNull *string           `json:"-"`
-	PID               UniqueIdentifier  `db:"p_id"`
-	SkipPID           UniqueIdentifier  `json:"-"`
-	PIDNull           *UniqueIdentifier `db:"p_idNull"`
-	SkipPIDNull       *UniqueIdentifier `tvp:"-"`
-	PVarbinary        []byte            `db:"p_varbinary"`
-	SkipPVarbinary    []byte            `json:"-" tvp:"-"`
-	PTinyint          int8              `db:"p_tinyint"`
-	SkipPTinyint      int8              `tvp:"-"`
-	PTinyintNull      *int8             `db:"p_tinyintNull"`
-	SkipPTinyintNull  *int8             `tvp:"-" json:"any"`
-	PSmallint         int16             `db:"p_smallint"`
-	SkipPSmallint     int16             `json:"-"`
-	PSmallintNull     *int16            `db:"p_smallintNull"`
-	SkipPSmallintNull *int16            `tvp:"-"`
-	PInt              int32             `db:"p_int"`
-	SkipPInt          int32             `json:"-"`
-	PIntNull          *int32            `db:"p_intNull"`
-	SkipPIntNull      *int32            `tvp:"-"`
-	PBigint           int64             `db:"p_bigint"`
-	SkipPBigint       int64             `tvp:"-"`
-	PBigintNull       *int64            `db:"p_bigintNull"`
-	SkipPBigintNull   *int64            `json:"any" tvp:"-"`
-	PBit              bool              `db:"p_bit"`
-	SkipPBit          bool              `json:"-"`
-	PBitNull          *bool             `db:"p_bitNull"`
-	SkipPBitNull      *bool             `json:"-"`
-	PFloat32          float32           `db:"p_float32"`
-	SkipPFloat32      float32           `tvp:"-"`
-	PFloatNull32      *float32          `db:"p_floatNull32"`
-	SkipPFloatNull32  *float32          `tvp:"-"`
-	PFloat64          float64           `db:"p_float64"`
-	SkipPFloat64      float64           `tvp:"-"`
-	PFloatNull64      *float64          `db:"p_floatNull64"`
-	SkipPFloatNull64  *float64          `tvp:"-"`
-	DTime             time.Time         `db:"p_timeNull"`
-	SkipDTime         time.Time         `tvp:"-"`
-	DTimeNull         *time.Time        `db:"p_time"`
-	SkipDTimeNull     *time.Time        `tvp:"-"`
-	Pint              int               `db:"p_int_null"`
-	SkipPint          int               `tvp:"-"`
-	PintNull          *int              `db:"p_int_"`
-	SkipPintNull      *int              `tvp:"-"`
+	PBinary           []byte                       `db:"p_binary"`
+	SkipPBinary       []byte                       `json:"-"`
+	PVarchar          string                       `db:"p_varchar"`
+	SkipPVarchar      string                       `tvp:"-"`
+	PVarcharNull      *string                      `db:"p_varcharNull"`
+	SkipPVarcharNull  *string                      `json:"-" tvp:"-"`
+	PNvarchar         string                       `db:"p_nvarchar"`
+	SkipPNvarchar     string                       `json:"-"`
+	PNvarcharNull     *string                      `db:"p_nvarcharNull"`
+	SkipPNvarcharNull *string                      `json:"-"`
+	PID               mssqltypes.UniqueIdentifier  `db:"p_id"`
+	SkipPID           mssqltypes.UniqueIdentifier  `json:"-"`
+	PIDNull           *mssqltypes.UniqueIdentifier `db:"p_idNull"`
+	SkipPIDNull       *mssqltypes.UniqueIdentifier `tvp:"-"`
+	PVarbinary        []byte                       `db:"p_varbinary"`
+	SkipPVarbinary    []byte                       `json:"-" tvp:"-"`
+	PTinyint          int8                         `db:"p_tinyint"`
+	SkipPTinyint      int8                         `tvp:"-"`
+	PTinyintNull      *int8                        `db:"p_tinyintNull"`
+	SkipPTinyintNull  *int8                        `tvp:"-" json:"any"`
+	PSmallint         int16                        `db:"p_smallint"`
+	SkipPSmallint     int16                        `json:"-"`
+	PSmallintNull     *int16                       `db:"p_smallintNull"`
+	SkipPSmallintNull *int16                       `tvp:"-"`
+	PInt              int32                        `db:"p_int"`
+	SkipPInt          int32                        `json:"-"`
+	PIntNull          *int32                       `db:"p_intNull"`
+	SkipPIntNull      *int32                       `tvp:"-"`
+	PBigint           int64                        `db:"p_bigint"`
+	SkipPBigint       int64                        `tvp:"-"`
+	PBigintNull       *int64                       `db:"p_bigintNull"`
+	SkipPBigintNull   *int64                       `json:"any" tvp:"-"`
+	PBit              bool                         `db:"p_bit"`
+	SkipPBit          bool                         `json:"-"`
+	PBitNull          *bool                        `db:"p_bitNull"`
+	SkipPBitNull      *bool                        `json:"-"`
+	PFloat32          float32                      `db:"p_float32"`
+	SkipPFloat32      float32                      `tvp:"-"`
+	PFloatNull32      *float32                     `db:"p_floatNull32"`
+	SkipPFloatNull32  *float32                     `tvp:"-"`
+	PFloat64          float64                      `db:"p_float64"`
+	SkipPFloat64      float64                      `tvp:"-"`
+	PFloatNull64      *float64                     `db:"p_floatNull64"`
+	SkipPFloatNull64  *float64                     `tvp:"-"`
+	DTime             time.Time                    `db:"p_timeNull"`
+	SkipDTime         time.Time                    `tvp:"-"`
+	DTimeNull         *time.Time                   `db:"p_time"`
+	SkipDTimeNull     *time.Time                   `tvp:"-"`
+	Pint              int                          `db:"p_int_null"`
+	SkipPint          int                          `tvp:"-"`
+	PintNull          *int                         `db:"p_int_"`
+	SkipPintNull      *int                         `tvp:"-"`
 }
 
 func TestTVP(t *testing.T) {
@@ -215,7 +217,7 @@ func TestTVP(t *testing.T) {
 			PBinary:    []byte("ccc"),
 			PVarchar:   varcharNull,
 			PNvarchar:  nvarchar,
-			PID:        UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PID:        mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PVarbinary: bytesMock,
 			PTinyint:   i8,
 			PSmallint:  i16,
@@ -231,7 +233,7 @@ func TestTVP(t *testing.T) {
 			PBinary:    []byte("www"),
 			PVarchar:   "eee",
 			PNvarchar:  "lll",
-			PID:        UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PID:        mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PVarbinary: []byte("zzz"),
 			PTinyint:   5,
 			PSmallint:  16000,
@@ -247,7 +249,7 @@ func TestTVP(t *testing.T) {
 			PBinary:       nil,
 			PVarcharNull:  &varcharNull,
 			PNvarcharNull: &nvarchar,
-			PIDNull:       &UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PIDNull:       &mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PTinyintNull:  &i8,
 			PSmallintNull: &i16,
 			PIntNull:      &i32,
@@ -263,7 +265,7 @@ func TestTVP(t *testing.T) {
 			PBinary:       []byte("www"),
 			PVarchar:      "eee",
 			PNvarchar:     "lll",
-			PIDNull:       &UniqueIdentifier{},
+			PIDNull:       &mssqltypes.UniqueIdentifier{},
 			PVarbinary:    []byte("zzz"),
 			PTinyint:      5,
 			PSmallint:     16000,
@@ -468,7 +470,7 @@ func TestTVP_WithTag(t *testing.T) {
 			PBinary:    []byte("ccc"),
 			PVarchar:   varcharNull,
 			PNvarchar:  nvarchar,
-			PID:        UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PID:        mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PVarbinary: bytesMock,
 			PTinyint:   i8,
 			PSmallint:  i16,
@@ -485,7 +487,7 @@ func TestTVP_WithTag(t *testing.T) {
 			PBinary:    []byte("www"),
 			PVarchar:   "eee",
 			PNvarchar:  "lll",
-			PID:        UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PID:        mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PVarbinary: []byte("zzz"),
 			PTinyint:   5,
 			PSmallint:  16000,
@@ -502,7 +504,7 @@ func TestTVP_WithTag(t *testing.T) {
 			PBinary:       nil,
 			PVarcharNull:  &varcharNull,
 			PNvarcharNull: &nvarchar,
-			PIDNull:       &UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
+			PIDNull:       &mssqltypes.UniqueIdentifier{0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF, 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF},
 			PTinyintNull:  &i8,
 			PSmallintNull: &i16,
 			PIntNull:      &i32,
@@ -518,7 +520,7 @@ func TestTVP_WithTag(t *testing.T) {
 			PBinary:       []byte("www"),
 			PVarchar:      "eee",
 			PNvarchar:     "lll",
-			PIDNull:       &UniqueIdentifier{},
+			PIDNull:       &mssqltypes.UniqueIdentifier{},
 			PVarbinary:    []byte("zzz"),
 			PTinyint:      5,
 			PSmallint:     16000,
diff --git a/types.go b/types.go
index b6e7fb2b..6bf297f7 100644
--- a/types.go
+++ b/types.go
@@ -11,7 +11,8 @@ import (
 	"time"
 
 	"github.com/denisenkom/go-mssqldb/internal/cp"
-	"github.com/denisenkom/go-mssqldb/internal/decimal"
+	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
+	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
 // fixed-length data types
@@ -338,7 +339,7 @@ func readFixedType(ti *typeInfo, r *tdsBuffer) interface{} {
 	case typeInt8:
 		return int64(binary.LittleEndian.Uint64(buf))
 	default:
-		badStreamPanicf("Invalid typeid")
+		mssqlerror.BadStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -353,7 +354,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 	switch ti.TypeId {
 	case typeDateN:
 		if len(buf) != 3 {
-			badStreamPanicf("Invalid size for DATENTYPE")
+			mssqlerror.BadStreamPanicf("Invalid size for DATENTYPE")
 		}
 		return decodeDate(buf)
 	case typeTimeN:
@@ -375,13 +376,13 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return int64(binary.LittleEndian.Uint64(buf))
 		default:
-			badStreamPanicf("Invalid size for INTNTYPE: %d", len(buf))
+			mssqlerror.BadStreamPanicf("Invalid size for INTNTYPE: %d", len(buf))
 		}
 	case typeDecimal, typeNumeric, typeDecimalN, typeNumericN:
 		return decodeDecimal(ti.Prec, ti.Scale, buf)
 	case typeBitN:
 		if len(buf) != 1 {
-			badStreamPanicf("Invalid size for BITNTYPE")
+			mssqlerror.BadStreamPanicf("Invalid size for BITNTYPE")
 		}
 		return buf[0] != 0
 	case typeFltN:
@@ -391,7 +392,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return math.Float64frombits(binary.LittleEndian.Uint64(buf))
 		default:
-			badStreamPanicf("Invalid size for FLTNTYPE")
+			mssqlerror.BadStreamPanicf("Invalid size for FLTNTYPE")
 		}
 	case typeMoneyN:
 		switch len(buf) {
@@ -400,7 +401,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return decodeMoney(buf)
 		default:
-			badStreamPanicf("Invalid size for MONEYNTYPE")
+			mssqlerror.BadStreamPanicf("Invalid size for MONEYNTYPE")
 		}
 	case typeDateTim4:
 		return decodeDateTim4(buf)
@@ -413,7 +414,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return decodeDateTime(buf)
 		default:
-			badStreamPanicf("Invalid size for DATETIMENTYPE")
+			mssqlerror.BadStreamPanicf("Invalid size for DATETIMENTYPE")
 		}
 	case typeChar, typeVarChar:
 		return decodeChar(ti.Collation, buf)
@@ -425,7 +426,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		copy(cpy, buf)
 		return cpy
 	default:
-		badStreamPanicf("Invalid typeid")
+		mssqlerror.BadStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -464,7 +465,7 @@ func readShortLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 	case typeUdt:
 		return decodeUdt(*ti, buf)
 	default:
-		badStreamPanicf("Invalid typeid")
+		mssqlerror.BadStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -512,7 +513,7 @@ func readLongLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 	case typeNText:
 		return decodeNChar(buf)
 	default:
-		badStreamPanicf("Invalid typeid")
+		mssqlerror.BadStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -645,7 +646,7 @@ func readVariantType(ti *typeInfo, r *tdsBuffer) interface{} {
 		r.ReadFull(buf)
 		return decodeNChar(buf)
 	default:
-		badStreamPanicf("Invalid variant typeid")
+		mssqlerror.BadStreamPanicf("Invalid variant typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -671,7 +672,7 @@ func readPLPType(ti *typeInfo, r *tdsBuffer) interface{} {
 			break
 		}
 		if _, err := io.CopyN(buf, r, int64(chunksize)); err != nil {
-			badStreamPanicf("Reading PLP type failed: %s", err.Error())
+			mssqlerror.BadStreamPanicf("Reading PLP type failed: %s", err.Error())
 		}
 	}
 	switch ti.TypeId {
@@ -725,7 +726,7 @@ func readVarLen(ti *typeInfo, r *tdsBuffer) {
 		case 5, 6, 7:
 			ti.Size = 5
 		default:
-			badStreamPanicf("Invalid scale for TIME/DATETIME2/DATETIMEOFFSET type")
+			mssqlerror.BadStreamPanicf("Invalid scale for TIME/DATETIME2/DATETIMEOFFSET type")
 		}
 		switch ti.TypeId {
 		case typeDateTime2N:
@@ -805,7 +806,7 @@ func readVarLen(ti *typeInfo, r *tdsBuffer) {
 			ti.Reader = readVariantType
 		}
 	default:
-		badStreamPanicf("Invalid type %d", ti.TypeId)
+		mssqlerror.BadStreamPanicf("Invalid type %d", ti.TypeId)
 	}
 	return
 }
@@ -819,12 +820,12 @@ func decodeMoney(buf []byte) []byte {
 		uint64(buf[1])<<40 |
 		uint64(buf[2])<<48 |
 		uint64(buf[3])<<56)
-	return decimal.ScaleBytes(strconv.FormatInt(money, 10), 4)
+	return mssqltypes.ScaleBytes(strconv.FormatInt(money, 10), 4)
 }
 
 func decodeMoney4(buf []byte) []byte {
 	money := int32(binary.LittleEndian.Uint32(buf[0:4]))
-	return decimal.ScaleBytes(strconv.FormatInt(int64(money), 10), 4)
+	return mssqltypes.ScaleBytes(strconv.FormatInt(int64(money), 10), 4)
 }
 
 func decodeGuid(buf []byte) []byte {
@@ -836,7 +837,7 @@ func decodeGuid(buf []byte) []byte {
 func decodeDecimal(prec uint8, scale uint8, buf []byte) []byte {
 	var sign uint8
 	sign = buf[0]
-	var dec decimal.Decimal
+	var dec mssqltypes.Decimal
 	dec.SetPositive(sign != 0)
 	dec.SetPrec(prec)
 	dec.SetScale(scale)
@@ -994,7 +995,7 @@ func decodeChar(col cp.Collation, buf []byte) string {
 func decodeUcs2(buf []byte) string {
 	res, err := ucs22str(buf)
 	if err != nil {
-		badStreamPanicf("Invalid UCS2 encoding: %s", err.Error())
+		mssqlerror.BadStreamPanicf("Invalid UCS2 encoding: %s", err.Error())
 	}
 	return res
 }

From 3dde7868fd453d585a5f41aaa25dbf6a99dc3bba Mon Sep 17 00:00:00 2001
From: v-kaywon <v-kaywon@microsoft.com>
Date: Wed, 11 Sep 2019 14:31:31 -0700
Subject: [PATCH 08/10] fix buf_test.go

---
 buf_test.go | 32 --------------------------------
 1 file changed, 32 deletions(-)

diff --git a/buf_test.go b/buf_test.go
index 76efbd1d..9d681665 100644
--- a/buf_test.go
+++ b/buf_test.go
@@ -282,35 +282,3 @@ func TestWrite_BufferBounds(t *testing.T) {
 		t.Fatal("FinishPacket failed:", err.Error())
 	}
 }
-
-func TestReadUsVarCharOrPanic(t *testing.T) {
-	memBuf := bytes.NewBuffer([]byte{3, 0, 0x31, 0, 0x32, 0, 0x33, 0})
-	s := readUsVarCharOrPanic(memBuf)
-	if s != "123" {
-		t.Errorf("UsVarChar expected to return 123 but it returned %s", s)
-	}
-
-	// test invalid usvarchar
-	defer func() {
-		recover()
-	}()
-	memBuf = bytes.NewBuffer([]byte{})
-	s = readUsVarCharOrPanic(memBuf)
-	t.Fatal("UsVarChar() should panic, but it didn't")
-}
-
-func TestReadBVarCharOrPanic(t *testing.T) {
-	memBuf := bytes.NewBuffer([]byte{3, 0x31, 0, 0x32, 0, 0x33, 0})
-	s := readBVarCharOrPanic(memBuf)
-	if s != "123" {
-		t.Errorf("readBVarCharOrPanic expected to return 123 but it returned %s", s)
-	}
-
-	// test invalid varchar
-	defer func() {
-		recover()
-	}()
-	memBuf = bytes.NewBuffer([]byte{})
-	s = readBVarCharOrPanic(memBuf)
-	t.Fatal("readBVarCharOrPanic() should panic on empty buffer, but it didn't")
-}

From 1844e8344ecc3dbb03955a41892cb80c5e5bd796 Mon Sep 17 00:00:00 2001
From: v-kaywon <v-kaywon@microsoft.com>
Date: Thu, 12 Sep 2019 17:14:27 -0700
Subject: [PATCH 09/10] update buf_test.go

---
 buf_test.go | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/buf_test.go b/buf_test.go
index 9d681665..76efbd1d 100644
--- a/buf_test.go
+++ b/buf_test.go
@@ -282,3 +282,35 @@ func TestWrite_BufferBounds(t *testing.T) {
 		t.Fatal("FinishPacket failed:", err.Error())
 	}
 }
+
+func TestReadUsVarCharOrPanic(t *testing.T) {
+	memBuf := bytes.NewBuffer([]byte{3, 0, 0x31, 0, 0x32, 0, 0x33, 0})
+	s := readUsVarCharOrPanic(memBuf)
+	if s != "123" {
+		t.Errorf("UsVarChar expected to return 123 but it returned %s", s)
+	}
+
+	// test invalid usvarchar
+	defer func() {
+		recover()
+	}()
+	memBuf = bytes.NewBuffer([]byte{})
+	s = readUsVarCharOrPanic(memBuf)
+	t.Fatal("UsVarChar() should panic, but it didn't")
+}
+
+func TestReadBVarCharOrPanic(t *testing.T) {
+	memBuf := bytes.NewBuffer([]byte{3, 0x31, 0, 0x32, 0, 0x33, 0})
+	s := readBVarCharOrPanic(memBuf)
+	if s != "123" {
+		t.Errorf("readBVarCharOrPanic expected to return 123 but it returned %s", s)
+	}
+
+	// test invalid varchar
+	defer func() {
+		recover()
+	}()
+	memBuf = bytes.NewBuffer([]byte{})
+	s = readBVarCharOrPanic(memBuf)
+	t.Fatal("readBVarCharOrPanic() should panic on empty buffer, but it didn't")
+}

From e6e91f5f31a94caf4b704d6720b0d8d580c418aa Mon Sep 17 00:00:00 2001
From: v-kaywon <v-kaywon@microsoft.com>
Date: Tue, 17 Sep 2019 16:26:52 -0700
Subject: [PATCH 10/10] pull error out of subpackage

---
 buf.go                                   |  10 +--
 internal/mssqlerror/error.go => error.go |   8 +-
 mssql.go                                 |   3 +-
 queries_go19_test.go                     |   5 +-
 queries_test.go                          |   7 +-
 token.go                                 | 110 +++++++++++------------
 types.go                                 |  31 ++++---
 7 files changed, 82 insertions(+), 92 deletions(-)
 rename internal/mssqlerror/error.go => error.go (87%)

diff --git a/buf.go b/buf.go
index e20d7aa1..ba39b40f 100644
--- a/buf.go
+++ b/buf.go
@@ -4,8 +4,6 @@ import (
 	"encoding/binary"
 	"errors"
 	"io"
-
-	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 )
 
 type packetType uint8
@@ -188,7 +186,7 @@ func (r *tdsBuffer) ReadByte() (res byte, err error) {
 func (r *tdsBuffer) byte() byte {
 	b, err := r.ReadByte()
 	if err != nil {
-		mssqlerror.BadStreamPanic(err)
+		badStreamPanic(err)
 	}
 	return b
 }
@@ -196,7 +194,7 @@ func (r *tdsBuffer) byte() byte {
 func (r *tdsBuffer) ReadFull(buf []byte) {
 	_, err := io.ReadFull(r, buf[:])
 	if err != nil {
-		mssqlerror.BadStreamPanic(err)
+		badStreamPanic(err)
 	}
 }
 
@@ -229,7 +227,7 @@ func (r *tdsBuffer) BVarChar() string {
 func readBVarCharOrPanic(r io.Reader) string {
 	s, err := readBVarChar(r)
 	if err != nil {
-		mssqlerror.BadStreamPanic(err)
+		badStreamPanic(err)
 	}
 	return s
 }
@@ -237,7 +235,7 @@ func readBVarCharOrPanic(r io.Reader) string {
 func readUsVarCharOrPanic(r io.Reader) string {
 	s, err := readUsVarChar(r)
 	if err != nil {
-		mssqlerror.BadStreamPanic(err)
+		badStreamPanic(err)
 	}
 	return s
 }
diff --git a/internal/mssqlerror/error.go b/error.go
similarity index 87%
rename from internal/mssqlerror/error.go
rename to error.go
index fe4ce619..6a0175c0 100644
--- a/internal/mssqlerror/error.go
+++ b/error.go
@@ -1,4 +1,4 @@
-package mssqlerror
+package mssql
 
 import (
 	"fmt"
@@ -73,12 +73,10 @@ func streamErrorf(format string, v ...interface{}) StreamError {
 	return StreamError{"Invalid TDS stream: " + fmt.Sprintf(format, v...)}
 }
 
-// BadStreamPanic calls panic with err.
-func BadStreamPanic(err error) {
+func badStreamPanic(err error) {
 	panic(err)
 }
 
-// BadStreamPanicf calls panic with a formatted error message as an invalid TDS stream error.
-func BadStreamPanicf(format string, v ...interface{}) {
+func badStreamPanicf(format string, v ...interface{}) {
 	panic(streamErrorf(format, v...))
 }
diff --git a/mssql.go b/mssql.go
index 2949163d..e37109cd 100644
--- a/mssql.go
+++ b/mssql.go
@@ -15,7 +15,6 @@ import (
 	"time"
 	"unicode"
 
-	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 	"github.com/denisenkom/go-mssqldb/internal/querytext"
 )
 
@@ -189,7 +188,7 @@ func (c *Conn) checkBadConn(err error) error {
 	case net.Error:
 		c.connectionGood = false
 		return err
-	case mssqlerror.StreamError:
+	case StreamError:
 		c.connectionGood = false
 		return err
 	default:
diff --git a/queries_go19_test.go b/queries_go19_test.go
index 5e86818d..222a034d 100644
--- a/queries_go19_test.go
+++ b/queries_go19_test.go
@@ -11,7 +11,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
@@ -227,7 +226,7 @@ END;
 
 		t.Run("should fail if destination has invalid type", func(t *testing.T) {
 			// Error type should not be supported
-			var err_out mssqlerror.Error
+			var err_out Error
 			_, err := db.ExecContext(ctx, sqltextrun,
 				sql.Named("bid", sql.Out{Dest: &err_out}),
 			)
@@ -247,7 +246,7 @@ END;
 
 		t.Run("should fail if parameter has invalid type", func(t *testing.T) {
 			// passing invalid parameter type
-			var err_val mssqlerror.Error
+			var err_val Error
 			_, err = db.ExecContext(ctx, sqltextrun, err_val)
 			if err == nil {
 				t.Error("Expected to fail but it didn't")
diff --git a/queries_test.go b/queries_test.go
index 1098899a..8f5c8d40 100644
--- a/queries_test.go
+++ b/queries_test.go
@@ -15,7 +15,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
@@ -622,7 +621,7 @@ func TestError(t *testing.T) {
 		t.Fatal("Query should fail")
 	}
 
-	if sqlerr, ok := err.(mssqlerror.Error); !ok {
+	if sqlerr, ok := err.(Error); !ok {
 		t.Fatalf("Should be sql error, actually %T, %v", err, err)
 	} else {
 		if sqlerr.Number != 2812 { // Could not find stored procedure 'bad'
@@ -972,7 +971,7 @@ func TestErrorInfo(t *testing.T) {
 	defer conn.Close()
 
 	_, err := conn.Exec("select bad")
-	if sqlError, ok := err.(mssqlerror.Error); ok {
+	if sqlError, ok := err.(Error); ok {
 		if sqlError.SQLErrorNumber() != 207 /*invalid column name*/ {
 			t.Errorf("Query failed with unexpected error number %d %s", sqlError.SQLErrorNumber(), sqlError.SQLErrorMessage())
 		}
@@ -983,7 +982,7 @@ func TestErrorInfo(t *testing.T) {
 		t.Error("Failed to convert error to SQLErorr", err)
 	}
 	_, err = conn.Exec("RAISERROR('test message', 18, 111)")
-	if sqlError, ok := err.(mssqlerror.Error); ok {
+	if sqlError, ok := err.(Error); ok {
 		if sqlError.SQLErrorNumber() != 50000 {
 			t.Errorf("Query failed with unexpected error number %d %s", sqlError.SQLErrorNumber(), sqlError.SQLErrorMessage())
 		}
diff --git a/token.go b/token.go
index 7b4bd4f0..1acac8a5 100644
--- a/token.go
+++ b/token.go
@@ -9,8 +9,6 @@ import (
 	"net"
 	"strconv"
 	"strings"
-
-	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 )
 
 //go:generate stringer -type token
@@ -89,18 +87,18 @@ type doneStruct struct {
 	Status   uint16
 	CurCmd   uint16
 	RowCount uint64
-	errors   []mssqlerror.Error
+	errors   []Error
 }
 
 func (d doneStruct) isError() bool {
 	return d.Status&doneError != 0 || len(d.errors) > 0
 }
 
-func (d doneStruct) getError() mssqlerror.Error {
+func (d doneStruct) getError() Error {
 	if len(d.errors) > 0 {
 		return d.errors[len(d.errors)-1]
 	} else {
-		return mssqlerror.Error{Message: "Request failed but didn't provide reason"}
+		return Error{Message: "Request failed but didn't provide reason"}
 	}
 }
 
@@ -139,127 +137,127 @@ func processEnvChg(sess *tdsSession) {
 			return
 		}
 		if err != nil {
-			mssqlerror.BadStreamPanic(err)
+			badStreamPanic(err)
 		}
 		switch envtype {
 		case envTypDatabase:
 			sess.database, err = readBVarChar(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			_, err = readBVarChar(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envTypLanguage:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// old value
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envTypCharset:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// old value
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envTypPacketSize:
 			packetsize, err := readBVarChar(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			_, err = readBVarChar(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			packetsizei, err := strconv.Atoi(packetsize)
 			if err != nil {
-				mssqlerror.BadStreamPanicf("Invalid Packet size value returned from server (%s): %s", packetsize, err.Error())
+				badStreamPanicf("Invalid Packet size value returned from server (%s): %s", packetsize, err.Error())
 			}
 			sess.buf.ResizeBuffer(packetsizei)
 		case envSortId:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envSortFlags:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envSqlCollation:
 			// currently ignored
 			var collationSize uint8
 			err = binary.Read(r, binary.LittleEndian, &collationSize)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 
 			// SQL Collation data should contain 5 bytes in length
 			if collationSize != 5 {
-				mssqlerror.BadStreamPanicf("Invalid SQL Collation size value returned from server: %d", collationSize)
+				badStreamPanicf("Invalid SQL Collation size value returned from server: %d", collationSize)
 			}
 
 			// 4 bytes, contains: LCID ColFlags Version
 			var info uint32
 			err = binary.Read(r, binary.LittleEndian, &info)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 
 			// 1 byte, contains: sortID
 			var sortID uint8
 			err = binary.Read(r, binary.LittleEndian, &sortID)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envTypBeginTran:
 			tranid, err := readBVarByte(r)
 			if len(tranid) != 8 {
-				mssqlerror.BadStreamPanicf("invalid size of transaction identifier: %d", len(tranid))
+				badStreamPanicf("invalid size of transaction identifier: %d", len(tranid))
 			}
 			sess.tranid = binary.LittleEndian.Uint64(tranid)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			if sess.logFlags&logTransaction != 0 {
 				sess.log.Printf("BEGIN TRANSACTION %x\n", sess.tranid)
 			}
 			_, err = readBVarByte(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envTypCommitTran, envTypRollbackTran:
 			_, err = readBVarByte(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			_, err = readBVarByte(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			if sess.logFlags&logTransaction != 0 {
 				if envtype == envTypCommitTran {
@@ -273,81 +271,81 @@ func processEnvChg(sess *tdsSession) {
 			// currently ignored
 			// new value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// old value
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envDefectTran:
 			// currently ignored
 			// new value
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envDatabaseMirrorPartner:
 			sess.partner, err = readBVarChar(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			_, err = readBVarChar(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envPromoteTran:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// dtc token
 			// spec says it should be L_VARBYTE, so this code might be wrong
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envTranMgrAddr:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// XACT_MANAGER_ADDRESS = B_VARBYTE
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envTranEnded:
 			// currently ignored
 			// old value, B_VARBYTE
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// should be 0
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envResetConnAck:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// should be 0
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envStartedInstanceName:
 			// currently ignored
 			// old value, should be 0
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// instance name
 			if _, err = readBVarChar(r); err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 		case envRouting:
 			// RoutingData message is:
@@ -357,24 +355,24 @@ func processEnvChg(sess *tdsSession) {
 			// AlternateServer             US_VARCHAR
 			_, err := readUshort(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			protocol, err := readByte(r)
 			if err != nil || protocol != 0 {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			newPort, err := readUshort(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			newServer, err := readUsVarChar(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			// consume the OLDVALUE = %x00 %x00
 			_, err = readUshort(r)
 			if err != nil {
-				mssqlerror.BadStreamPanic(err)
+				badStreamPanic(err)
 			}
 			sess.routedServer = newServer
 			sess.routedPort = newPort
@@ -443,7 +441,7 @@ func parseLoginAck(r *tdsBuffer) loginAckStruct {
 	prognamelen := buf[1+4]
 	var err error
 	if res.ProgName, err = ucs22str(buf[1+4+1 : 1+4+1+prognamelen*2]); err != nil {
-		mssqlerror.BadStreamPanic(err)
+		badStreamPanic(err)
 	}
 	res.ProgVer = binary.BigEndian.Uint32(buf[size-4:])
 	return res
@@ -491,7 +489,7 @@ func parseNbcRow(r *tdsBuffer, columns []columnStruct, row []interface{}) {
 }
 
 // http://msdn.microsoft.com/en-us/library/dd304156.aspx
-func parseError72(r *tdsBuffer) (res mssqlerror.Error) {
+func parseError72(r *tdsBuffer) (res Error) {
 	length := r.uint16()
 	_ = length // ignore length
 	res.Number = r.int32()
@@ -505,7 +503,7 @@ func parseError72(r *tdsBuffer) (res mssqlerror.Error) {
 }
 
 // http://msdn.microsoft.com/en-us/library/dd304156.aspx
-func parseInfo(r *tdsBuffer) (res mssqlerror.Error) {
+func parseInfo(r *tdsBuffer) (res Error) {
 	length := r.uint16()
 	_ = length // ignore length
 	res.Number = r.int32()
@@ -560,10 +558,10 @@ func processSingleResponse(sess *tdsSession, ch chan tokenStruct, outs map[strin
 		return
 	}
 	if packet_type != packReply {
-		mssqlerror.BadStreamPanic(fmt.Errorf("unexpected packet type in reply: got %v, expected %v", packet_type, packReply))
+		badStreamPanic(fmt.Errorf("unexpected packet type in reply: got %v, expected %v", packet_type, packReply))
 	}
 	var columns []columnStruct
-	errs := make([]mssqlerror.Error, 0, 5)
+	errs := make([]Error, 0, 5)
 	for {
 		token := token(sess.buf.byte())
 		if sess.logFlags&logDebug != 0 {
@@ -648,7 +646,7 @@ func processSingleResponse(sess *tdsSession, ch chan tokenStruct, outs map[strin
 				}
 			}
 		default:
-			mssqlerror.BadStreamPanic(fmt.Errorf("unknown token type returned: %v", token))
+			badStreamPanic(fmt.Errorf("unknown token type returned: %v", token))
 		}
 	}
 }
diff --git a/types.go b/types.go
index 6bf297f7..497d3abf 100644
--- a/types.go
+++ b/types.go
@@ -11,7 +11,6 @@ import (
 	"time"
 
 	"github.com/denisenkom/go-mssqldb/internal/cp"
-	"github.com/denisenkom/go-mssqldb/internal/mssqlerror"
 	"github.com/denisenkom/go-mssqldb/internal/mssqltypes"
 )
 
@@ -339,7 +338,7 @@ func readFixedType(ti *typeInfo, r *tdsBuffer) interface{} {
 	case typeInt8:
 		return int64(binary.LittleEndian.Uint64(buf))
 	default:
-		mssqlerror.BadStreamPanicf("Invalid typeid")
+		badStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -354,7 +353,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 	switch ti.TypeId {
 	case typeDateN:
 		if len(buf) != 3 {
-			mssqlerror.BadStreamPanicf("Invalid size for DATENTYPE")
+			badStreamPanicf("Invalid size for DATENTYPE")
 		}
 		return decodeDate(buf)
 	case typeTimeN:
@@ -376,13 +375,13 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return int64(binary.LittleEndian.Uint64(buf))
 		default:
-			mssqlerror.BadStreamPanicf("Invalid size for INTNTYPE: %d", len(buf))
+			badStreamPanicf("Invalid size for INTNTYPE: %d", len(buf))
 		}
 	case typeDecimal, typeNumeric, typeDecimalN, typeNumericN:
 		return decodeDecimal(ti.Prec, ti.Scale, buf)
 	case typeBitN:
 		if len(buf) != 1 {
-			mssqlerror.BadStreamPanicf("Invalid size for BITNTYPE")
+			badStreamPanicf("Invalid size for BITNTYPE")
 		}
 		return buf[0] != 0
 	case typeFltN:
@@ -392,7 +391,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return math.Float64frombits(binary.LittleEndian.Uint64(buf))
 		default:
-			mssqlerror.BadStreamPanicf("Invalid size for FLTNTYPE")
+			badStreamPanicf("Invalid size for FLTNTYPE")
 		}
 	case typeMoneyN:
 		switch len(buf) {
@@ -401,7 +400,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return decodeMoney(buf)
 		default:
-			mssqlerror.BadStreamPanicf("Invalid size for MONEYNTYPE")
+			badStreamPanicf("Invalid size for MONEYNTYPE")
 		}
 	case typeDateTim4:
 		return decodeDateTim4(buf)
@@ -414,7 +413,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		case 8:
 			return decodeDateTime(buf)
 		default:
-			mssqlerror.BadStreamPanicf("Invalid size for DATETIMENTYPE")
+			badStreamPanicf("Invalid size for DATETIMENTYPE")
 		}
 	case typeChar, typeVarChar:
 		return decodeChar(ti.Collation, buf)
@@ -426,7 +425,7 @@ func readByteLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 		copy(cpy, buf)
 		return cpy
 	default:
-		mssqlerror.BadStreamPanicf("Invalid typeid")
+		badStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -465,7 +464,7 @@ func readShortLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 	case typeUdt:
 		return decodeUdt(*ti, buf)
 	default:
-		mssqlerror.BadStreamPanicf("Invalid typeid")
+		badStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -513,7 +512,7 @@ func readLongLenType(ti *typeInfo, r *tdsBuffer) interface{} {
 	case typeNText:
 		return decodeNChar(buf)
 	default:
-		mssqlerror.BadStreamPanicf("Invalid typeid")
+		badStreamPanicf("Invalid typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -646,7 +645,7 @@ func readVariantType(ti *typeInfo, r *tdsBuffer) interface{} {
 		r.ReadFull(buf)
 		return decodeNChar(buf)
 	default:
-		mssqlerror.BadStreamPanicf("Invalid variant typeid")
+		badStreamPanicf("Invalid variant typeid")
 	}
 	panic("shoulnd't get here")
 }
@@ -672,7 +671,7 @@ func readPLPType(ti *typeInfo, r *tdsBuffer) interface{} {
 			break
 		}
 		if _, err := io.CopyN(buf, r, int64(chunksize)); err != nil {
-			mssqlerror.BadStreamPanicf("Reading PLP type failed: %s", err.Error())
+			badStreamPanicf("Reading PLP type failed: %s", err.Error())
 		}
 	}
 	switch ti.TypeId {
@@ -726,7 +725,7 @@ func readVarLen(ti *typeInfo, r *tdsBuffer) {
 		case 5, 6, 7:
 			ti.Size = 5
 		default:
-			mssqlerror.BadStreamPanicf("Invalid scale for TIME/DATETIME2/DATETIMEOFFSET type")
+			badStreamPanicf("Invalid scale for TIME/DATETIME2/DATETIMEOFFSET type")
 		}
 		switch ti.TypeId {
 		case typeDateTime2N:
@@ -806,7 +805,7 @@ func readVarLen(ti *typeInfo, r *tdsBuffer) {
 			ti.Reader = readVariantType
 		}
 	default:
-		mssqlerror.BadStreamPanicf("Invalid type %d", ti.TypeId)
+		badStreamPanicf("Invalid type %d", ti.TypeId)
 	}
 	return
 }
@@ -995,7 +994,7 @@ func decodeChar(col cp.Collation, buf []byte) string {
 func decodeUcs2(buf []byte) string {
 	res, err := ucs22str(buf)
 	if err != nil {
-		mssqlerror.BadStreamPanicf("Invalid UCS2 encoding: %s", err.Error())
+		badStreamPanicf("Invalid UCS2 encoding: %s", err.Error())
 	}
 	return res
 }