[CALCITE-3018] User defined scalar function which returns a Date/Timestamp value causes error.

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.19.0
• Component/s: core
• Assignee: Unassigned
• Reporter: Yincheng Fang
• Created: 24/Apr/19 11:06
• Updated: 11/Jun/21 12:09

Description

I've defined a user defined function that returns a date or timestamp and register it on root schema :

    public static java.sql.Date test(long value) {
        return new java.sql.Date(value);
    }

 

    rootSchema.add("my_test", ScalarFunctionImpl.create(CalciteTest.class, "test")); 

 

If I use this function in the select part of a query as the only column, the result works fine:

    select my_test(1)  from northwind.product

However, if I add an additional column in the select part, the error occurs:

    select my_test(1), 2  from northwind.product

Error message:

 

 Exception in thread "main" java.lang.ClassCastException: java.sql.Date cannot be cast to java.lang.Number
    at org.apache.calcite.avatica.util.AbstractCursor$NumberAccessor.getNumber(AbstractCursor.java:726)
    at org.apache.calcite.avatica.util.AbstractCursor$DateFromNumberAccessor.getDate(AbstractCursor.java:915)
    at org.apache.calcite.avatica.AvaticaSite.get(AvaticaSite.java:326)
    at org.apache.calcite.avatica.AvaticaResultSet.getObject(AvaticaResultSet.java:393)

 

 I tried with calcite.debug=true, and the difference seems as follows:

• 1 column

 

/*  51 */             public Object current() {
/*  52 */               return org.apache.calcite.runtime.SqlFunctions.toIntOptional(CalciteTest.test(1));
/*  53 */             }

 

• 2 columns

/*  51 */             public Object current() {
/*  52 */               return new Object[] {
/*  53 */                   CalciteTest.test(1),
/*  54 */                   2};
/*  55 */             }

Issue Links

• is duplicated by: CALCITE-3019 User defined scalar function which returns a Date/Timestamp value causes error.