(calcite) branch main updated: [CALCITE-6228] ELEMENT function infers incorrect return type

[mbudiu]

This is an automated email from the ASF dual-hosted git repository.

mbudiu pushed a commit to branch main
in repository https://gitbox.apache.org/repos/asf/calcite.git


The following commit(s) were added to refs/heads/main by this push:
     new f837ffa877 [CALCITE-6228] ELEMENT function infers incorrect return type
f837ffa877 is described below

commit f837ffa877c5b7f795fd175532f6ec9db4440533
Author: Mihai Budiu <mbu...@feldera.com>
AuthorDate: Wed Feb 7 06:41:23 2024 -0800

    [CALCITE-6228] ELEMENT function infers incorrect return type
    
    Signed-off-by: Mihai Budiu <mbu...@feldera.com>
---
 .../org/apache/calcite/sql/fun/SqlStdOperatorTable.java    |  2 +-
 .../main/java/org/apache/calcite/sql/type/ReturnTypes.java |  7 ++++---
 .../java/org/apache/calcite/test/SqlValidatorTest.java     | 14 +++++++-------
 .../main/java/org/apache/calcite/test/SqlOperatorTest.java |  2 +-
 4 files changed, 13 insertions(+), 12 deletions(-)

diff --git 
a/core/src/main/java/org/apache/calcite/sql/fun/SqlStdOperatorTable.java 
b/core/src/main/java/org/apache/calcite/sql/fun/SqlStdOperatorTable.java
index 4b07e5ad01..16151967a3 100644
--- a/core/src/main/java/org/apache/calcite/sql/fun/SqlStdOperatorTable.java
+++ b/core/src/main/java/org/apache/calcite/sql/fun/SqlStdOperatorTable.java
@@ -2103,7 +2103,7 @@ public class SqlStdOperatorTable extends 
ReflectiveSqlOperatorTable {
    */
   public static final SqlFunction ELEMENT =
       SqlBasicFunction.create("ELEMENT",
-          ReturnTypes.MULTISET_ELEMENT_NULLABLE,
+          ReturnTypes.MULTISET_ELEMENT_FORCE_NULLABLE,
           OperandTypes.COLLECTION);
 
   /**
diff --git a/core/src/main/java/org/apache/calcite/sql/type/ReturnTypes.java 
b/core/src/main/java/org/apache/calcite/sql/type/ReturnTypes.java
index 5924f001d0..f8696893b0 100644
--- a/core/src/main/java/org/apache/calcite/sql/type/ReturnTypes.java
+++ b/core/src/main/java/org/apache/calcite/sql/type/ReturnTypes.java
@@ -615,10 +615,11 @@ public abstract class ReturnTypes {
       ARG0.andThen(SqlTypeTransforms.TO_MULTISET);
 
   /**
-   * Returns the element type of a MULTISET.
+   * Returns the element type of a MULTISET, with nullability enforced.
    */
-  public static final SqlReturnTypeInference MULTISET_ELEMENT_NULLABLE =
-      MULTISET.andThen(SqlTypeTransforms.TO_COLLECTION_ELEMENT_TYPE);
+  public static final SqlReturnTypeInference MULTISET_ELEMENT_FORCE_NULLABLE =
+      MULTISET.andThen(SqlTypeTransforms.TO_COLLECTION_ELEMENT_TYPE)
+          .andThen(SqlTypeTransforms.FORCE_NULLABLE);
 
   /**
    * Same as {@link #MULTISET} but returns with nullability if any of the
diff --git a/core/src/test/java/org/apache/calcite/test/SqlValidatorTest.java 
b/core/src/test/java/org/apache/calcite/test/SqlValidatorTest.java
index 8fead2ce72..f888d4e3ea 100644
--- a/core/src/test/java/org/apache/calcite/test/SqlValidatorTest.java
+++ b/core/src/test/java/org/apache/calcite/test/SqlValidatorTest.java
@@ -1925,17 +1925,17 @@ public class SqlValidatorTest extends 
SqlValidatorTestCase {
 
   @Test void testElement() {
     expr("element(multiset[1])")
-        .columnType("INTEGER NOT NULL");
+        .columnType("INTEGER");
     expr("1.0+element(multiset[1])")
-        .columnType("DECIMAL(12, 1) NOT NULL");
+        .columnType("DECIMAL(12, 1)");
     expr("element(multiset['1'])")
-        .columnType("CHAR(1) NOT NULL");
+        .columnType("CHAR(1)");
     expr("element(multiset[1e-2])")
-        .columnType("DOUBLE NOT NULL");
+        .columnType("DOUBLE");
     expr("element(multiset[multiset[cast(null as tinyint)]])")
-        .columnType("TINYINT MULTISET NOT NULL");
-    // Test case for <a 
href="https://issues.apache.org/jira/projects/CALCITE/issues/CALCITE-6227";>
-    // ELEMENT(NULL) causes an assertion failure</a>.
+        .columnType("TINYINT MULTISET");
+    // Test case for 
https://issues.apache.org/jira/projects/CALCITE/issues/CALCITE-6227
+    // ELEMENT(NULL) causes an assertion failure.
     expr("element(null)")
         .columnType("NULL");
   }
diff --git a/testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java 
b/testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java
index badde6f889..4b4e8fd4b8 100644
--- a/testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java
+++ b/testkit/src/main/java/org/apache/calcite/test/SqlOperatorTest.java
@@ -9816,7 +9816,7 @@ public class SqlOperatorTest {
   @Test void testElementFunc() {
     final SqlOperatorFixture f = fixture();
     f.setFor(SqlStdOperatorTable.ELEMENT, VM_FENNEL, VM_JAVA);
-    f.checkString("element(multiset['abc'])", "abc", "CHAR(3) NOT NULL");
+    f.checkString("element(multiset['abc'])", "abc", "CHAR(3)");
     f.checkNull("element(multiset[cast(null as integer)])");
   }