Feature/76 select from values as (#84)

* #76: Added `SELECT FROM VALUES ... AS` support
exasol · Jun 30, 2020 · 222ff94 · 222ff94
1 parent c6a44c8
commit 222ff94
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diff --git a/README.md b/README.md
@@ -53,6 +53,7 @@ final String sql = renderer.render();
 * [User Guide](doc/user_guide/user_guide.md)
 * [API Documentation](https://javadoc.io/doc/com.exasol/sql-statement-builder)
 * [MIT License](LICENSE)
+* [Changelog](doc/changes/changelog.md)
 
 ### Information for Developers
 

diff --git a/doc/changes/changes-4.0.0.md b/doc/changes/changes-4.0.0.md
@@ -8,6 +8,7 @@
 
 * #80: Added ossindex-maven-plugin and versions-maven-plugin, updated dependencies.
 * #81: Ported from Java 8 to Java 11.
+* #76: Added `SELECT FROM VALUES ... AS` support.
 
 ## Dependency updates
 

diff --git a/src/main/java/com/exasol/sql/ValueTable.java b/src/main/java/com/exasol/sql/ValueTable.java
@@ -11,6 +11,8 @@
 // [impl->dsn~value-table~1]
 public class ValueTable extends AbstractFragment {
     private final List<ValueTableRow> rows = new ArrayList<>();
+    private String tableNameAlias;
+    private final List<String> columnNameAliases = new ArrayList<>();
 
     /**
      * Create a new {@link ValueTable}.
@@ -173,4 +175,45 @@ public void accept(final ValueTableVisitor visitor) {
         }
         visitor.leave(this);
     }
-}
+
+    /**
+     * Set alias for the value table.
+     * 
+     * @param tableNameAlias table name alias
+     * @param columnNameAliases zero or more column names aliases
+     */
+    public void alias(final String tableNameAlias, final String... columnNameAliases) {
+        this.tableNameAlias = tableNameAlias;
+        if (columnNameAliases.length > 0) {
+            this.columnNameAliases.addAll(Arrays.asList(columnNameAliases));
+        }
+    }
+
+    /**
+     * CHeck if the value table has an alias.
+     * 
+     * @return true if the value table has an alias
+     */
+    public boolean hasAlias() {
+        return (this.tableNameAlias != null) && (!this.tableNameAlias.isEmpty()) //
+                && (!this.columnNameAliases.isEmpty());
+    }
+
+    /**
+     * Get a table name alias.
+     * 
+     * @return table name alias
+     */
+    public String getTableNameAlias() {
+        return this.tableNameAlias;
+    }
+
+    /**
+     * Get column name aliases.
+     * 
+     * @return column name aliases
+     */
+    public List<String> getColumnNameAliases() {
+        return this.columnNameAliases;
+    }
+}
diff --git a/src/main/java/com/exasol/sql/dql/select/FromClause.java b/src/main/java/com/exasol/sql/dql/select/FromClause.java
@@ -34,7 +34,7 @@ public FromClause table(final String name) {
     }
 
     /**
-     * Add a table name with an an alias to the {@link FromClause}.
+     * Add a table name with an alias to the {@link FromClause}.
      *
      * @param name table name
      * @param as table alias
@@ -56,6 +56,21 @@ public FromClause valueTable(final ValueTable valueTable) {
         return this;
     }
 
+    /**
+     * Create a {@link FromClause} from a value table and an alias.
+     *
+     * @param valueTable table of value expressions
+     * @param tableNameAlias table alias
+     * @param columnNameAliases columns aliases
+     * @return parent {@code FROM} clause
+     */
+    public FromClause valueTableAs(final ValueTable valueTable, final String tableNameAlias,
+            final String... columnNameAliases) {
+        valueTable.alias(tableNameAlias, columnNameAliases);
+        this.valueTables.add(valueTable);
+        return this;
+    }
+
     /**
      * Create a new {@link Join} that belongs to a {@code FROM} clause.
      *

diff --git a/src/main/java/com/exasol/sql/dql/select/rendering/SelectRenderer.java b/src/main/java/com/exasol/sql/dql/select/rendering/SelectRenderer.java
@@ -1,5 +1,7 @@
 package com.exasol.sql.dql.select.rendering;
 
+import java.util.List;
+
 import com.exasol.sql.*;
 import com.exasol.sql.dql.select.*;
 import com.exasol.sql.expression.BooleanExpression;
@@ -129,6 +131,19 @@ public void visit(final ValueTable valueTable) {
     @Override
     public void leave(final ValueTable valueTable) {
         append(")");
+        if (valueTable.hasAlias()) {
+            appendKeyWord(" AS ");
+            appendAutoQuoted(valueTable.getTableNameAlias());
+            append("(");
+            final List<String> columnNameAliases = valueTable.getColumnNameAliases();
+            for (int i = 0; i < columnNameAliases.size(); i++) {
+                appendAutoQuoted(columnNameAliases.get(i));
+                if (i < columnNameAliases.size() - 1) {
+                    append(", ");
+                }
+            }
+            append(")");
+        }
         setLastVisited(valueTable);
     }
 

diff --git a/src/test/java/com/exasol/sql/dql/select/rendering/TestSelectRendering.java b/src/test/java/com/exasol/sql/dql/select/rendering/TestSelectRendering.java
@@ -97,7 +97,7 @@ void testSelectWithQuotedIdentifiersDoesNotAddExtraQuotes() {
     @Test
     void testQuotedIdentifiers() {
         final StringRendererConfig config = StringRendererConfig.builder().quoteIdentifiers(true).build();
-        Select select = this.select.all();
+        final Select select = this.select.all();
         select.from().table("person");
         select.where(eq(ExpressionTerm.stringLiteral("foo"), ColumnReference.of("test")));
         assertThat(select, rendersWithConfigTo(config, "SELECT * FROM \"person\" WHERE 'foo' = \"test\""));

diff --git a/src/test/java/com/exasol/sql/dql/select/rendering/TestValueTableRendering.java b/src/test/java/com/exasol/sql/dql/select/rendering/TestValueTableRendering.java
@@ -1,6 +1,7 @@
 package com.exasol.sql.dql.select.rendering;
 
 import static com.exasol.hamcrest.SqlFragmentRenderResultMatcher.rendersTo;
+import static com.exasol.hamcrest.SqlFragmentRenderResultMatcher.rendersWithConfigTo;
 import static org.hamcrest.MatcherAssert.assertThat;
 
 import org.junit.jupiter.api.BeforeEach;
@@ -9,6 +10,7 @@
 import com.exasol.sql.StatementFactory;
 import com.exasol.sql.ValueTable;
 import com.exasol.sql.dql.select.Select;
+import com.exasol.sql.rendering.StringRendererConfig;
 
 class TestValueTableRendering {
     private Select select;
@@ -26,4 +28,34 @@ void testSelectFromMultipleTableAs() {
         assertThat(this.select.all().from().valueTable(values),
                 rendersTo("SELECT * FROM (VALUES ('r1c1', 'r1c2'), ('r2c1', 'r2c2'))"));
     }
+
+    @Test
+    void testSelectFromValuesAs() {
+        final ValueTable values = new ValueTable(this.select);
+        values.add(1, 2);
+        final Select select = this.select.field("COL1");
+        select.from().valueTableAs(values, "T", "COL1", "COL2");
+        assertThat(select, rendersTo("SELECT COL1 FROM (VALUES (1, 2)) AS T(COL1, COL2)"));
+    }
+
+    @Test
+    void testSelectFromValuesAsWithQuotation() {
+        final StringRendererConfig config = StringRendererConfig.builder().quoteIdentifiers(true).build();
+        final ValueTable values = new ValueTable(this.select);
+        values.add(1, 2);
+        final Select select = this.select.field("COL1");
+        select.from().valueTableAs(values, "T", "COL1", "COL2");
+        assertThat(select,
+                rendersWithConfigTo(config, "SELECT \"COL1\" FROM (VALUES (1, 2)) AS \"T\"(\"COL1\", \"COL2\")"));
+    }
+
+    @Test
+    void testSelectFromValuesAsWithQuotationOneColumn() {
+        final StringRendererConfig config = StringRendererConfig.builder().quoteIdentifiers(true).build();
+        final ValueTable values = new ValueTable(this.select);
+        values.add(1);
+        final Select select = this.select.field("COL1");
+        select.from().valueTableAs(values, "T", "COL1");
+        assertThat(select, rendersWithConfigTo(config, "SELECT \"COL1\" FROM (VALUES (1)) AS \"T\"(\"COL1\")"));
+    }
 }