#56: Support column references in value expressions (#58)

* #56: Support column references in value expressions
exasol · Dec 5, 2019 · df0b293 · df0b293
1 parent 43dd149
commit df0b293
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diff --git a/doc/user_guide/common_constructs/value_tables.md b/doc/user_guide/common_constructs/value_tables.md
@@ -0,0 +1,11 @@
+# Value Tables
+
+Value tables are lists of content definitions for rows. They can appear in [`INSERT`](../statements/insert.md) and [`MERGE`](../statements/merge.md) statements.
+
+## Defining Value Tables
+
+The class `ValueTable` contains multiple methods for defining value tables.
+
+The `appendRow()` methods allow adding all values for a complete row at once. They are especially useful in case all columns have the same type.
+
+The `add()` methods on the other hand amend the last row with an additional value.
diff --git a/doc/user_guide/statements/merge.md b/doc/user_guide/statements/merge.md
@@ -68,6 +68,10 @@ merge.using("src") //
     .where(gt(column("src", "c5"), integerLiteral(1000)));
 ```
 
+### Using Value Tables in `MERGE` Insert Clauses
+
+In the insert clause of a merge statement, you can use `VALUES` to insert [value tables](../common_constructs/value_tables.md).
+
 ### Rendering `MERGE` Statements
 
 Use the `MergeRenderer` to render `Merge` objects into SQL strings.

diff --git a/launch/sql-statement-builder mvn package.launch b/launch/sql-statement-builder mvn package.launch
@@ -15,6 +15,6 @@
 <listAttribute key="org.eclipse.debug.ui.favoriteGroups">
 <listEntry value="org.eclipse.debug.ui.launchGroup.run"/>
 </listAttribute>
-<stringAttribute key="org.eclipse.jdt.launching.JRE_CONTAINER" value="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/java-1.8.0-openjdk-1.8.0.181-7.b13.fc28.x86_64"/>
+<stringAttribute key="org.eclipse.jdt.launching.JRE_CONTAINER" value="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/java-1.8.0-openjdk-1.8.0.222.b10-0.fc30.x86_64"/>
 <stringAttribute key="org.eclipse.jdt.launching.WORKING_DIRECTORY" value="${workspace_loc:/sql-statement-builder}"/>
 </launchConfiguration>
diff --git a/pom.xml b/pom.xml
@@ -4,7 +4,7 @@
   <modelVersion>4.0.0</modelVersion>
   <groupId>com.exasol</groupId>
   <artifactId>sql-statement-builder</artifactId>
-  <version>3.1.0</version>
+  <version>3.2.0</version>
   <name>Exasol SQL Statement Builder</name>
   <description>This module provides a Builder for SQL statements that helps creating the correct structure and validates variable parts of the statements.</description>
   <url>https://github.com/exasol/sql-statement-builder</url>

diff --git a/src/main/java/com/exasol/sql/ValueTable.java b/src/main/java/com/exasol/sql/ValueTable.java
@@ -1,18 +1,19 @@
 package com.exasol.sql;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.util.*;
+
+import com.exasol.sql.expression.ValueExpression;
 
 /**
- * Value tables are pseudo-tables constructed from rows and columns of expressions (e.g. literals)
+ * Value tables are pseudo-tables constructed from rows and columns of expressions (e.g. literals).
  *
  */
 // [impl->dsn~value-table~1]
 public class ValueTable extends AbstractFragment {
     private final List<ValueTableRow> rows = new ArrayList<>();
 
     /**
-     * Create a new {@link ValueTable}
+     * Create a new {@link ValueTable}.
      *
      * @param root SQL statement this table belongs to
      */
@@ -21,7 +22,7 @@ public ValueTable(final Fragment root) {
     }
 
     /**
-     * Append a value table row consisting of value literals to the value table
+     * Append a value table row consisting of value literals to the value table.
      *
      * @param literals literals to be appended
      *
@@ -33,7 +34,7 @@ public ValueTable appendRow(final String... literals) {
     }
 
     /**
-     * Append a {@link ValueTableRow} to the {@link ValueTable}
+     * Append a {@link ValueTableRow} to the {@link ValueTable}.
      *
      * @param row row to be appended
      *
@@ -45,7 +46,7 @@ public ValueTable appendRow(final ValueTableRow row) {
     }
 
     /**
-     * Get a list of all rows in the value table
+     * Get a list of all rows in the value table.
      *
      * @return rows
      */
@@ -54,22 +55,14 @@ public List<ValueTableRow> getRows() {
     }
 
     /**
-     * Adds values to the last row of the value table
+     * Add string values to the last row of the value table.
      *
      * @param values values to be added
      */
     public void add(final String... values) {
         amendLastRow(createLastRowBuilder().add(values).build());
     }
 
-    private ValueTableRow.Builder createLastRowBuilder() {
-        final ValueTableRow.Builder builder = ValueTableRow.builder(this.root);
-        if (!isEmpty()) {
-            builder.add(getLastRow().getExpressions());
-        }
-        return builder;
-    }
-
     private synchronized void amendLastRow(final ValueTableRow row) {
         if (isEmpty()) {
             this.rows.add(row);
@@ -79,14 +72,42 @@ private synchronized void amendLastRow(final ValueTableRow row) {
 
     }
 
+    private ValueTableRow.Builder createLastRowBuilder() {
+        final ValueTableRow.Builder builder = ValueTableRow.builder(this.root);
+        if (!isEmpty()) {
+            builder.add(getLastRow().getExpressions());
+        }
+        return builder;
+    }
+
+    /**
+     * Add integer values to the last row of the value table.
+     *
+     * @param values values to be added
+     */
     public void add(final int... values) {
         amendLastRow(createLastRowBuilder().add(values).build());
     }
 
+    /**
+     * Add an unnamed placeholder to the value table.
+     * <p>
+     * Unnamed placeholders are the "?" in a prepared statement which are replaced by the actual variable values.
+     * </p>
+     */
     public void addPlaceholder() {
         amendLastRow(createLastRowBuilder().addPlaceholder().build());
     }
 
+    /**
+     * Add a list of value expressions to the last row of the value table.
+     *
+     * @param expressions value expressions to be added
+     */
+    public void add(final ValueExpression... expressions) {
+        amendLastRow(createLastRowBuilder().add(Arrays.asList(expressions)).build());
+    }
+
     private ValueTableRow getLastRow() {
         return this.rows.get(this.rows.size() - 1);
     }
@@ -95,6 +116,11 @@ protected boolean isEmpty() {
         return this.rows.isEmpty();
     }
 
+    /**
+     * Accept a visitor.
+     * 
+     * @param visitor to be accepted
+     */
     public void accept(final ValueTableVisitor visitor) {
         visitor.visit(this);
         for (final ValueTableRow row : this.rows) {

diff --git a/src/main/java/com/exasol/sql/ValueTableRow.java b/src/main/java/com/exasol/sql/ValueTableRow.java
@@ -12,9 +12,9 @@ public class ValueTableRow extends AbstractFragment {
     private final List<ValueExpression> expressions;
 
     /**
-     * Create a value table row from a list of expressions
+     * Create a value table row from a list of expressions.
      *
-     * @param root        root node of the SQL statement
+     * @param root root node of the SQL statement
      * @param expressions value expressions
      */
     public ValueTableRow(final Fragment root, final ValueExpression... expressions) {
@@ -23,9 +23,9 @@ public ValueTableRow(final Fragment root, final ValueExpression... expressions)
     }
 
     /**
-     * Create a value table row from a list of string literals
+     * Create a value table row from a list of string literals.
      *
-     * @param root   root node of the SQL statement
+     * @param root root node of the SQL statement
      * @param values sting literals
      */
     public ValueTableRow(final Fragment root, final String... values) {
@@ -42,21 +42,26 @@ private ValueTableRow(final Builder builder) {
     }
 
     /**
-     * Get the list of expressions the row consists of
+     * Get the list of expressions the row consists of.
      *
      * @return list of expressions
      */
     public List<ValueExpression> getExpressions() {
         return this.expressions;
     }
 
+    /**
+     * Accept a visitor.
+     * 
+     * @param visitor to accept.
+     */
     public void accept(final ValueTableVisitor visitor) {
         visitor.visit(this);
         visitor.leave(this);
     }
 
     /**
-     * Get a {@link Builder} for a {@link ValueTableRow}
+     * Get a {@link Builder} for a {@link ValueTableRow}.
      *
      * @param root root fragment of the SQL statement
      *
@@ -78,7 +83,7 @@ public Builder(final Fragment root) {
         }
 
         /**
-         * Add one or more string literals to the row
+         * Add one or more string literals to the row.
          *
          * @param values strings to be added
          * @return <code>this</code> for fluent programming
@@ -91,7 +96,7 @@ public Builder add(final String... values) {
         }
 
         /**
-         * Add one or more integer literals to the row
+         * Add one or more integer literals to the row.
          *
          * @param values integers to be added
          * @return <code>this</code> for fluent programming
@@ -114,7 +119,7 @@ public Builder addPlaceholder() {
         }
 
         /**
-         * Add a list of expressions to the {@link ValueTableRow}
+         * Add a list of expressions to the {@link ValueTableRow}.
          *
          * @param expressions expressions to be added
          * @return <code>this</code> for fluent programming
@@ -125,7 +130,7 @@ public Builder add(final List<ValueExpression> expressions) {
         }
 
         /**
-         * Build a new {@link ValueTableRow}
+         * Build a new {@link ValueTableRow}.
          *
          * @return new {@link ValueTableRow}
          */

diff --git a/src/main/java/com/exasol/sql/dml/insert/AbstractInsertValueTable.java b/src/main/java/com/exasol/sql/dml/insert/AbstractInsertValueTable.java
@@ -1,6 +1,7 @@
 package com.exasol.sql.dml.insert;
 
 import com.exasol.sql.*;
+import com.exasol.sql.expression.ValueExpression;
 
 /**
  * Abstract base class for SQL fragments that contain a insert value table (for example {@code INSERT}, {@code MERGE}).
@@ -82,6 +83,19 @@ public T values(final int... values) {
         return self();
     }
 
+    /**
+     * Insert a list of value expressions.
+     *
+     * @param expressions value expressions to be inserted
+     * @return <code>this</code> for fluent programming
+     */
+    // [impl->dsn~values-as-insert-source~1]
+    public T values(final ValueExpression... expressions) {
+        createInsertValueInstanceIfItDoesNotExist();
+        this.insertValueTable.add(expressions);
+        return self();
+    }
+
     /**
      * Add an unnamed value placeholder to the value list (this is useful for prepared statements).
      *

diff --git a/src/test/java/com/exasol/sql/dml/merge/rendering/MergeRenderingTest.java b/src/test/java/com/exasol/sql/dml/merge/rendering/MergeRenderingTest.java
@@ -157,4 +157,17 @@ void testComplexMerge() {
                 + " WHEN MATCHED THEN UPDATE SET c2 = DEFAULT, c3 = 'foo', c4 = 42" //
                 + " WHEN NOT MATCHED THEN INSERT (c3, c5) VALUES ('foo', 'bar')"));
     }
+
+    @Test
+    void testColumnReferenceInInsertValueList() {
+        this.merge //
+                .using("src") //
+                .on(eq(column("src", "c1"), column("dst", "c1"))) //
+                .whenNotMatched() //
+                .thenInsert() //
+                .field("c2") //
+                .values(column("src", "c2"));
+        assertThat(this.merge, rendersTo("MERGE INTO dst USING src ON src.c1 = dst.c1" //
+                + " WHEN NOT MATCHED THEN INSERT (c2) VALUES (src.c2)"));
+    }
 }