add transaction support

coredb/engine.go

@@ -43,6 +43,7 @@ func getDB(dbname string, mode DBMode) *sql.DB {
 }
 
 // FetchByPK returns a row of T type with given primary key value
+//
 // Deprecated: use the function with context
 func FetchByPK[T any](dbname string, tableName string, pkName []string, val ...any) *T {
 	sql := "WHERE `" + pkName[0] + "` = ?"
@@ -54,6 +55,7 @@ func FetchByPK[T any](dbname string, tableName string, pkName []string, val ...a
 }
 
 // FetchByPKs returns rows of T type with given primary key values
+//
 // Deprecated: use the function with context
 func FetchByPKs[T any](dbname string, tableName string, pkName string, vals []any) []*T {
 	if len(vals) == 0 {
@@ -71,6 +73,7 @@ func FetchByPKs[T any](dbname string, tableName string, pkName string, vals []an
 }
 
 // FetchByPKFromMaster returns a row of T type with given primary key value
+//
 // Deprecated: use the function with context
 func FetchByPKFromMaster[T any](dbname string, tableName string, pkName []string, val ...any) *T {
 	sql := "WHERE `" + pkName[0] + "` = ?"
@@ -82,6 +85,7 @@ func FetchByPKFromMaster[T any](dbname string, tableName string, pkName []string
 }
 
 // FetchByPKsFromMaster returns rows of T type with given primary key values
+//
 // Deprecated: use the function with context
 func FetchByPKsFromMaster[T any](dbname string, tableName string, pkName string, vals []any) []*T {
 	if len(vals) == 0 {
@@ -99,13 +103,15 @@ func FetchByPKsFromMaster[T any](dbname string, tableName string, pkName string,
 }
 
 // Exec given query with given db info & params
+//
 // Deprecated: use the function with context
 func Exec(dbname string, query string, params ...any) (sql.Result, error) {
 	mydb := getDB(dbname, DBModeWrite)
 	return mydb.Exec(query, params...)
 }
 
 // FindOne returns a row from given table type with where query
+//
 // Deprecated: use the function with context
 func FindOne[T any](dbname string, tableName string, where WhereQuery) *T {
 	u := new(T)
@@ -131,6 +137,7 @@ func FindOne[T any](dbname string, tableName string, where WhereQuery) *T {
 }
 
 // Find returns rows from given table type with where query
+//
 // Deprecated: use the function with context
 func Find[T any](dbname string, tableName string, where WhereQuery) ([]*T, error) {
 	columnsNames := GetColumnsNames[T]()
@@ -142,6 +149,7 @@ func Find[T any](dbname string, tableName string, where WhereQuery) ([]*T, error
 }
 
 // FindOneFromMaster using master DB returns a row from given table type with where query
+//
 // Deprecated: use the function with context
 func FindOneFromMaster[T any](dbname string, tableName string, where WhereQuery) *T {
 	u := new(T)
@@ -167,6 +175,7 @@ func FindOneFromMaster[T any](dbname string, tableName string, where WhereQuery)
 }
 
 // FindFromMaster using master DB returns rows from given table type with where query
+//
 // Deprecated: use the function with context
 func FindFromMaster[T any](dbname string, tableName string, where WhereQuery) ([]*T, error) {
 	columnsNames := GetColumnsNames[T]()
@@ -178,22 +187,25 @@ func FindFromMaster[T any](dbname string, tableName string, where WhereQuery) ([
 }
 
 // QueryInt single int result by query, handy for count(*) querys
+//
 // Deprecated: use the function with context
 func QueryInt(dbname string, query string, params ...any) (result int, err error) {
 	mydb := getDB(dbname, DBModeRead)
-	mydb.QueryRow(query, params...).Scan(&result)
+	err = mydb.QueryRow(query, params...).Scan(&result)
 	return
 }
 
 // QueryIntFromMaster single int result by query, handy for count(*) querys
+//
 // Deprecated: use the function with context
 func QueryIntFromMaster(dbname string, query string, params ...any) (result int, err error) {
 	mydb := getDB(dbname, DBModeReadFromWrite)
-	mydb.QueryRow(query, params...).Scan(&result)
+	err = mydb.QueryRow(query, params...).Scan(&result)
 	return
 }
 
 // Query rows from given table type with where query & params
+//
 // Deprecated: use the function with context
 func Query[T any](dbname string, query string, params ...any) (result []*T, err error) {
 	mydb := getDB(dbname, DBModeRead)
@@ -217,6 +229,7 @@ func Query[T any](dbname string, query string, params ...any) (result []*T, err
 }
 
 // Query rows from master DB from given table type with where query & params
+//
 // Deprecated: use the function with context
 func QueryFromMaster[T any](dbname string, query string, params ...any) (result []*T, err error) {
 	mydb := getDB(dbname, DBModeReadFromWrite)
@@ -244,7 +257,8 @@ func GetColumnsNames[T any]() (joinedColumnNames string) {
 	var o *T
 	t := reflect.TypeOf(o)
 	typeColumnNamesLock.RLock()
-	joinedColumnNames, ok := typeColumnNames[t]
+	var ok bool
+	joinedColumnNames, ok = typeColumnNames[t]
 	typeColumnNamesLock.RUnlock()
 	if ok {
 		return
@@ -269,15 +283,48 @@ func GetColumnsNames[T any]() (joinedColumnNames string) {
 	return
 }
 
-// StrutForScan returns value pointers of given obj
-func StrutForScan[T any](u *T) (pointers []any) {
-	val := reflect.ValueOf(u).Elem()
-	pointers = make([]any, 0, val.NumField())
+// GetColumnsNamesReflect returns column names joined by `,` of given type
+func GetColumnsNamesReflect(o any) (joinedColumnNames string) {
+	t := reflect.TypeOf(o)
+	elemType := t.Elem()
+	switch t.Kind() {
+	case reflect.Ptr:
+		// 是指针，尝试获取其指向的元素类型
+		if elemType.Kind() == reflect.Slice {
+			elemType = elemType.Elem().Elem() // 如果指针指向切片，获取切片元素的类型
+		}
+	case reflect.Slice:
+		// 是切片，获取切片元素的类型
+		if elemType.Kind() == reflect.Ptr {
+			elemType = elemType.Elem() // 切片元素是指针，获取其指向的类型
+		}
+	default:
+		// 既不是指针也不是切片，返回错误
+		panic("coredb: o is neither a pointer nor a slice")
+	}
+
+	typeColumnNamesLock.RLock()
+	var ok bool
+	joinedColumnNames, ok = typeColumnNames[elemType]
+	typeColumnNamesLock.RUnlock()
+	if ok {
+		return
+	}
+
+	var columnNames []string
+	val := reflect.New(elemType).Elem()
 	for i := 0; i < val.NumField(); i++ {
 		valueField := val.Field(i)
 		if f, ok := valueField.Addr().Interface().(ColumnType); ok {
-			pointers = append(pointers, f.GetValPointer())
+			columnNames = append(columnNames, "`"+f.GetColumnName()+"`")
 		}
 	}
+
+	joinedColumnNames = strings.Join(columnNames, ",")
+
+	typeColumnNamesLock.Lock()
+	typeColumnNames[t] = joinedColumnNames
+	typeColumnNamesLock.Unlock()
+
 	return
 }

coredb/engine_ctx.go

@@ -129,14 +129,14 @@ func FindFromMasterCtx[T any](ctx context.Context, dbname string, tableName stri
 // QueryIntCtx single int result by query, handy for count(*) querys
 func QueryIntCtx(ctx context.Context, dbname string, query string, params ...any) (result int, err error) {
 	mydb := getDB(dbname, DBModeRead)
-	mydb.QueryRowContext(ctx, query, params...).Scan(&result)
+	err = mydb.QueryRowContext(ctx, query, params...).Scan(&result)
 	return
 }
 
 // QueryIntFromMasterCtx single int result by query, handy for count(*) querys
 func QueryIntFromMasterCtx(ctx context.Context, dbname string, query string, params ...any) (result int, err error) {
 	mydb := getDB(dbname, DBModeReadFromWrite)
-	mydb.QueryRowContext(ctx, query, params...).Scan(&result)
+	err = mydb.QueryRowContext(ctx, query, params...).Scan(&result)
 	return
 }
 

coredb/scan.go

@@ -0,0 +1,121 @@
+package coredb
+
+import (
+	"database/sql"
+	"reflect"
+)
+
+// An InvalidScanError describes an invalid argument passed to Scan.
+type InvalidScanError struct {
+	Type reflect.Type
+}
+
+func (e *InvalidScanError) Error() string {
+	if e.Type == nil {
+		return "coredb: target is nil"
+	}
+
+	if e.Type.Kind() != reflect.Pointer {
+		return "coredb: target must be a non-nil pointer, got " + e.Type.String()
+	}
+	return "coredb: nil " + e.Type.String() + ")"
+}
+
+// RowsToStructSlice converts the rows of a SQL query result into a slice of structs.
+//
+// It takes a pointer to a sql.Rows object as input.
+// The function also uses a generic type T, which represents the type of the struct.
+//
+// The function returns a slice of pointers to T structs and an error.
+func RowsToStructSlice[T any](rows *sql.Rows) (result []*T, err error) {
+	var u *T
+	for rows.Next() {
+		u = new(T)
+		data := StrutForScan(u)
+		err = rows.Scan(data...)
+		if err != nil {
+			return
+		}
+		result = append(result, u)
+	}
+	err = rows.Err()
+	return
+}
+
+// RowToStruct converts a database row into a struct.
+//
+// It takes a pointer to a sql.Row and returns a pointer to the converted struct and an error.
+func RowToStruct[T any](row *sql.Row) (result *T, err error) {
+	result = new(T)
+	data := StrutForScan(result)
+	err = row.Scan(data...)
+	if err == sql.ErrNoRows {
+		err = nil
+	}
+	return
+}
+
+// StrutForScan returns value pointers of given obj
+func StrutForScan(u any) (pointers []any) {
+	val := reflect.ValueOf(u).Elem()
+	pointers = make([]any, 0, val.NumField())
+	for i := 0; i < val.NumField(); i++ {
+		valueField := val.Field(i)
+		if f, ok := valueField.Addr().Interface().(ColumnType); ok {
+			pointers = append(pointers, f.GetValPointer())
+		}
+	}
+	return
+}
+
+func RowsToStructSliceReflect(rows *sql.Rows, out any) (err error) {
+	if rows == nil {
+		return
+	}
+	sliceValue := reflect.ValueOf(out)
+	if sliceValue.Kind() != reflect.Ptr || sliceValue.IsNil() {
+		panic(&InvalidScanError{Type: sliceValue.Type()})
+	}
+	sliceValue = sliceValue.Elem()
+	if sliceValue.Kind() != reflect.Slice {
+		panic(&InvalidScanError{Type: reflect.TypeOf(out)})
+	}
+	elementType := sliceValue.Type().Elem()
+	if elementType.Kind() != reflect.Ptr {
+		panic(&InvalidScanError{Type: reflect.TypeOf(out)})
+	}
+	elementType = elementType.Elem()
+
+	var elements []reflect.Value
+	for rows.Next() {
+		v := reflect.New(elementType)
+		data := StrutForScan(v.Interface())
+		err = rows.Scan(data...)
+		if err != nil {
+			return
+		}
+		elements = append(elements, v.Elem())
+	}
+
+	sliceValue.Set(reflect.MakeSlice(sliceValue.Type(), len(elements), len(elements)))
+	for i, v := range elements {
+		sliceValue.Index(i).Set(v.Addr())
+	}
+
+	err = rows.Err()
+	return
+}
+
+func RowToStructReflect(row *sql.Row, v any) (err error) {
+	rv := reflect.ValueOf(v)
+	if rv.Kind() != reflect.Pointer || rv.IsNil() {
+		panic(&InvalidScanError{reflect.TypeOf(v)})
+	}
+
+	data := StrutForScan(v)
+	err = row.Scan(data...)
+	if err == sql.ErrNoRows {
+		return nil
+	}
+	return
+}