[CALCITE-6343] Fix AS alias operator stripping MEASUREness from measures

When inferring the return type of an operator application, don't unwrap MEASURE types if the operator is an AS alias.
apache · Mar 26, 2024 · 8bdf2ec · 8bdf2ec
1 parent d5b6b5c
commit 8bdf2ec
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diff --git a/core/src/main/java/org/apache/calcite/sql/SqlOperator.java b/core/src/main/java/org/apache/calcite/sql/SqlOperator.java
@@ -539,7 +539,9 @@ public RelDataType inferReturnType(
       }
 
       // MEASURE wrapper should be removed, e.g. MEASURE<DOUBLE> should just be DOUBLE
-      if (isMeasure(returnType) && returnType.getMeasureElementType() != null) {
+      if (opBinding.getOperator().kind != SqlKind.AS
+          && isMeasure(returnType)
+          && returnType.getMeasureElementType() != null) {
         returnType = Objects.requireNonNull(returnType.getMeasureElementType());
       }
 

diff --git a/core/src/test/java/org/apache/calcite/sql/type/RelDataTypeSystemTest.java b/core/src/test/java/org/apache/calcite/sql/type/RelDataTypeSystemTest.java
@@ -189,6 +189,15 @@ static class Fixture extends SqlTypeFixture {
     assertThat(dataType, is(innerType));
   }
 
+  @Test void testAsOperatorReturnTypeInferenceDoesNotRemoveMeasure() {
+    final SqlTypeFactoryImpl f = new Fixture().typeFactory;
+    RelDataType innerType = f.createSqlType(SqlTypeName.DOUBLE);
+    RelDataType measureType = f.createMeasureType(innerType);
+    RelDataType dataType = SqlStdOperatorTable.AS.inferReturnType(f,
+        Lists.newArrayList(measureType));
+    assertThat(dataType, is(measureType));
+  }
+
   @Test void testCustomDecimalPlusReturnTypeInference() {
     final SqlTypeFactoryImpl f = new Fixture().customTypeFactory;
     RelDataType operand1 = f.createSqlType(SqlTypeName.DECIMAL, 38, 10);