Add concat and textcat SQL functions (#6005)

docs/content/querying/sql.md

@@ -125,6 +125,8 @@ String functions accept strings, and return a type appropriate to the function.
 |Function|Notes|
 |--------|-----|
 |`x \|\| y`|Concat strings x and y.|
+|`CONCAT(expr, expr...)`|Concats a list of expressions.|
+|`TEXTCAT(expr, expr)`|Two argument version of CONCAT.|
 |`LENGTH(expr)`|Length of expr in UTF-16 code units.|
 |`CHAR_LENGTH(expr)`|Synonym for `LENGTH`.|
 |`CHARACTER_LENGTH(expr)`|Synonym for `LENGTH`.|

sql/src/main/java/io/druid/sql/calcite/expression/builtin/ConcatOperatorConversion.java

@@ -0,0 +1,72 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package io.druid.sql.calcite.expression.builtin;
+
+import io.druid.sql.calcite.expression.DruidExpression;
+import io.druid.sql.calcite.expression.OperatorConversions;
+import io.druid.sql.calcite.expression.SqlOperatorConversion;
+import io.druid.sql.calcite.planner.Calcites;
+import io.druid.sql.calcite.planner.PlannerContext;
+import io.druid.sql.calcite.table.RowSignature;
+import org.apache.calcite.rex.RexNode;
+import org.apache.calcite.sql.SqlFunction;
+import org.apache.calcite.sql.SqlFunctionCategory;
+import org.apache.calcite.sql.SqlKind;
+import org.apache.calcite.sql.type.OperandTypes;
+import org.apache.calcite.sql.type.ReturnTypes;
+import org.apache.calcite.sql.type.SqlTypeName;
+
+public class ConcatOperatorConversion implements SqlOperatorConversion
+{
+  private static final SqlFunction SQL_FUNCTION = new SqlFunction(
+      "CONCAT",
+      SqlKind.OTHER_FUNCTION,
+      ReturnTypes.explicit(
+          factory -> Calcites.createSqlType(factory, SqlTypeName.VARCHAR)
+      ),
+      null,
+      OperandTypes.SAME_VARIADIC,
+      SqlFunctionCategory.STRING
+  );
+
+  @Override
+  public SqlFunction calciteOperator()
+  {
+    return SQL_FUNCTION;
+  }
+
+  @Override
+  public DruidExpression toDruidExpression(
+      final PlannerContext plannerContext,
+      final RowSignature rowSignature,
+      final RexNode rexNode
+  )
+  {
+    return OperatorConversions.convertCall(
+        plannerContext,
+        rowSignature,
+        rexNode,
+        druidExpressions -> DruidExpression.of(
+            null,
+            DruidExpression.functionCall("concat", druidExpressions)
+        )
+    );
+  }
+}

sql/src/main/java/io/druid/sql/calcite/expression/builtin/TextcatOperatorConversion.java

@@ -0,0 +1,66 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package io.druid.sql.calcite.expression.builtin;
+
+import io.druid.sql.calcite.expression.DruidExpression;
+import io.druid.sql.calcite.expression.OperatorConversions;
+import io.druid.sql.calcite.expression.SqlOperatorConversion;
+import io.druid.sql.calcite.planner.PlannerContext;
+import io.druid.sql.calcite.table.RowSignature;
+import org.apache.calcite.rex.RexNode;
+import org.apache.calcite.sql.SqlFunction;
+import org.apache.calcite.sql.SqlFunctionCategory;
+import org.apache.calcite.sql.type.SqlTypeFamily;
+import org.apache.calcite.sql.type.SqlTypeName;
+
+public class TextcatOperatorConversion implements SqlOperatorConversion
+{
+  private static final SqlFunction SQL_FUNCTION = OperatorConversions
+      .operatorBuilder("textcat")
+      .operandTypes(SqlTypeFamily.CHARACTER, SqlTypeFamily.CHARACTER)
+      .requiredOperands(2)
+      .returnType(SqlTypeName.VARCHAR)
+      .functionCategory(SqlFunctionCategory.STRING)
+      .build();
+
+  @Override
+  public SqlFunction calciteOperator()
+  {
+    return SQL_FUNCTION;
+  }
+
+  @Override
+  public DruidExpression toDruidExpression(
+      final PlannerContext plannerContext,
+      final RowSignature rowSignature,
+      final RexNode rexNode
+  )
+  {
+    return OperatorConversions.convertCall(
+        plannerContext,
+        rowSignature,
+        rexNode,
+        druidExpressions -> DruidExpression.of(
+            null,
+            DruidExpression.functionCall("concat", druidExpressions)
+        )
+    );
+  }
+}

sql/src/main/java/io/druid/sql/calcite/planner/DruidOperatorTable.java

@@ -42,6 +42,7 @@ import io.druid.sql.calcite.expression.UnarySuffixOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.BTrimOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.CastOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.CeilOperatorConversion;
+import io.druid.sql.calcite.expression.builtin.ConcatOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.DateTruncOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.ExtractOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.FloorOperatorConversion;
@@ -52,6 +53,7 @@ import io.druid.sql.calcite.expression.builtin.RegexpExtractOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.ReinterpretOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.StrposOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.SubstringOperatorConversion;
+import io.druid.sql.calcite.expression.builtin.TextcatOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.TimeArithmeticOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.TimeExtractOperatorConversion;
 import io.druid.sql.calcite.expression.builtin.TimeFloorOperatorConversion;
@@ -146,6 +148,8 @@ public class DruidOperatorTable implements SqlOperatorTable
           .add(new RegexpExtractOperatorConversion())
           .add(new StrposOperatorConversion())
           .add(new SubstringOperatorConversion())
+          .add(new ConcatOperatorConversion())
+          .add(new TextcatOperatorConversion())
           .add(new AliasedOperatorConversion(new SubstringOperatorConversion(), "SUBSTR"))
           .add(new TimeArithmeticOperatorConversion.TimeMinusIntervalOperatorConversion())
           .add(new TimeArithmeticOperatorConversion.TimePlusIntervalOperatorConversion())

sql/src/test/java/io/druid/sql/calcite/CalciteQueryTest.java

@@ -6824,6 +6824,114 @@ public class CalciteQueryTest extends CalciteTestBase
     );
   }
 
+  @Test
+  public void testConcat() throws Exception
+  {
+    testQuery(
+        "SELECT CONCAT(dim1, '-', dim1, '_', dim1) as dimX FROM foo",
+        ImmutableList.of(
+            newScanQueryBuilder()
+                .dataSource(CalciteTests.DATASOURCE1)
+                .intervals(QSS(Filtration.eternity()))
+                .virtualColumns(EXPRESSION_VIRTUAL_COLUMN(
+                    "v0",
+                    "concat(\"dim1\",'-',\"dim1\",'_',\"dim1\")",
+                    ValueType.STRING
+                ))
+                .columns("v0")
+                .resultFormat(ScanQuery.RESULT_FORMAT_COMPACTED_LIST)
+                .context(QUERY_CONTEXT_DEFAULT)
+                .build()
+        ),
+        ImmutableList.of(
+            new Object[]{"-_"},
+            new Object[]{"10.1-10.1_10.1"},
+            new Object[]{"2-2_2"},
+            new Object[]{"1-1_1"},
+            new Object[]{"def-def_def"},
+            new Object[]{"abc-abc_abc"}
+        )
+    );
+
+    testQuery(
+        "SELECT CONCAT(dim1, CONCAT(dim2,'x'), m2, 9999, dim1) as dimX FROM foo",
+        ImmutableList.of(
+            newScanQueryBuilder()
+                .dataSource(CalciteTests.DATASOURCE1)
+                .intervals(QSS(Filtration.eternity()))
+                .virtualColumns(EXPRESSION_VIRTUAL_COLUMN(
+                    "v0",
+                    "concat(\"dim1\",concat(\"dim2\",'x'),\"m2\",9999,\"dim1\")",
+                    ValueType.STRING
+                ))
+                .columns("v0")
+                .resultFormat(ScanQuery.RESULT_FORMAT_COMPACTED_LIST)
+                .context(QUERY_CONTEXT_DEFAULT)
+                .build()
+        ),
+        ImmutableList.of(
+            new Object[]{"ax1.09999"},
+            new Object[]{"10.1x2.0999910.1"},
+            new Object[]{"2x3.099992"},
+            new Object[]{"1ax4.099991"},
+            new Object[]{"defabcx5.09999def"},
+            new Object[]{"abcx6.09999abc"}
+        )
+    );
+  }
+
+  @Test
+  public void testTextcat() throws Exception
+  {
+    testQuery(
+        "SELECT textcat(dim1, dim1) as dimX FROM foo",
+        ImmutableList.of(
+            newScanQueryBuilder()
+                .dataSource(CalciteTests.DATASOURCE1)
+                .intervals(QSS(Filtration.eternity()))
+                .virtualColumns(EXPRESSION_VIRTUAL_COLUMN("v0", "concat(\"dim1\",\"dim1\")", ValueType.STRING))
+                .columns("v0")
+                .resultFormat(ScanQuery.RESULT_FORMAT_COMPACTED_LIST)
+                .context(QUERY_CONTEXT_DEFAULT)
+                .build()
+        ),
+        ImmutableList.of(
+            new Object[]{""},
+            new Object[]{"10.110.1"},
+            new Object[]{"22"},
+            new Object[]{"11"},
+            new Object[]{"defdef"},
+            new Object[]{"abcabc"}
+        )
+    );
+
+    testQuery(
+        "SELECT textcat(dim1, CAST(m2 as VARCHAR)) as dimX FROM foo",
+        ImmutableList.of(
+            newScanQueryBuilder()
+                .dataSource(CalciteTests.DATASOURCE1)
+                .intervals(QSS(Filtration.eternity()))
+                .virtualColumns(EXPRESSION_VIRTUAL_COLUMN(
+                    "v0",
+                    "concat(\"dim1\",CAST(\"m2\", 'STRING'))",
+                    ValueType.STRING
+                ))
+                .columns("v0")
+                .resultFormat(ScanQuery.RESULT_FORMAT_COMPACTED_LIST)
+                .context(QUERY_CONTEXT_DEFAULT)
+                .build()
+        ),
+        ImmutableList.of(
+            new Object[]{"1.0"},
+            new Object[]{"10.12.0"},
+            new Object[]{"23.0"},
+            new Object[]{"14.0"},
+            new Object[]{"def5.0"},
+            new Object[]{"abc6.0"}
+        )
+    );
+  }
+
   private void testQuery(
       final String sql,
       final List<Query> expectedQueries,