[CALCITE-4265] Improve error message when CAST to unknown type

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.27.0
• Labels: pull-request-available
• Assignee: Danny Chen
• Reporter: Julian Hyde
• Created: 18/Sep/20 19:55
• Updated: 18/Jun/21 08:43
• Resolved: 22/Feb/21 06:58

Description

Improve error message when CAST to unknown type. If you add the following test case to RelToSqlConverterTest, you get an UnsupportedOperationException during validation due to the unknown datatype SIGNED:

@Test void testSelectFromUnionGrouping() {
    String query = "SELECT CASE WHEN \"t3\".\"groupingVal\" IN (0, 1) THEN \"t\".\"fname\" ELSE NULL END AS name, "
        + "CASE WHEN \"t3\".\"groupingVal\" = 0 THEN \"t\".\"birthdate\" ELSE NULL END AS birthdate, AVG(\"t\".\"__f2\") AS "
    + "\"__f2\", CAST(CASE WHEN \"t3\".\"groupingVal\" = 0 THEN 0 ELSE 1 END AS SIGNED) AS \"__f3\", CAST(CASE WHEN"
    + " \"t3\".\"groupingVal\" IN (0, 1) THEN 0 ELSE 1 END + CASE WHEN \"t3\".\"groupingVal\" = 0 THEN 0 ELSE 2 "
    + "END AS SIGNED) AS \"__f4\"\n"
        + "FROM (SELECT \"fname\", \"birthdate\", \"total_children\" + 2 AS \"__f2\"\n"
        + "FROM \"foodmart\".\"customer\") AS \"t\",\n"
        + "(SELECT 0 AS \"groupingVal\"\n"
        + "UNION ALL\n"
        + "SELECT 1 AS \"groupingVal\"\n"
        + "UNION ALL\n"
        + "SELECT 2 AS \"groupingVal\") AS \"t3\"\n"
        + "GROUP BY CASE WHEN \"t3\".\"groupingVal\" IN (0, 1) THEN \"t\".\"fname\" ELSE NULL END, CASE WHEN \"t3\""
        + ".\"groupingVal\" = 0 THEN \"t\".\"birthdate\" ELSE NULL END, \"t3\".\"groupingVal\"";
    sql(query).ok("--");
  }

throws

java.lang.UnsupportedOperationException: class org.apache.calcite.sql.SqlIdentifier: SIGNED
	at org.apache.calcite.util.Util.needToImplement(Util.java:1074)
	at org.apache.calcite.sql.validate.SqlValidatorImpl.getValidatedNodeType(SqlValidatorImpl.java:1655)
	at org.apache.calcite.sql.SqlUserDefinedTypeNameSpec.deriveType(SqlUserDefinedTypeNameSpec.java:49)
	at org.apache.calcite.sql.SqlDataTypeSpec.deriveType(SqlDataTypeSpec.java:222)
	at org.apache.calcite.sql.SqlDataTypeSpec.deriveType(SqlDataTypeSpec.java:209)
	at org.apache.calcite.sql.validate.SqlValidatorImpl$DeriveTypeVisitor.visit(SqlValidatorImpl.java:5868)
	at org.apache.calcite.sql.validate.SqlValidatorImpl$DeriveTypeVisitor.visit(SqlValidatorImpl.java:5753)
	at org.apache.calcite.sql.SqlDataTypeSpec.accept(SqlDataTypeSpec.java:186)

If you change SIGNED to INTEGER the exception goes away.

Clearly this test case is not minimal. There could probably be a 1 line test case for SqlValidatorTest.

Issue Links

• links to: GitHub Pull Request #2312
• links to: GitHub Pull Request #2326