[DERBY-5130] Allow for LONG VARCHAR to be compared to LONG VARCHAR

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 10.7.1.1
• Component/s: SQL
• Labels: comparison derby_triage10_8 sql typesystem
• Urgency: Normal
• Issue & fix info: Workaround attached
• Assignee: Unassigned
• Reporter: Lukas Eder
• Created: 12/Mar/11 17:17
• Updated: 15/Mar/11 18:11

Description

Interestingly, this is not possible:

select 1 from SYSIBM.SYSDUMMY1 where cast('2' as long varchar) = cast('2' as long varchar)

Whereas these statements are executable:

select 1 from SYSIBM.SYSDUMMY1 where '2' = '2'
select 1 from SYSIBM.SYSDUMMY1 where cast(cast('2' as long varchar) as varchar(1)) = cast(cast('2' as long varchar) as varchar(1))

According to the documentation that is the correct behaviour:
http://db.apache.org/derby/docs/10.7/ref/rrefsqlj58560.html

Nevertheless, if casting is possible between LONG VARCHAR and VARCHAR, and assignment too, then I don't understand why LONG VARCHAR cannot even be compared to LONG VARCHAR

Note: A similar issue has been open for a long time:
https://issues.apache.org/jira/browse/DERBY-342

Issue Links

• is related to: DERBY-342 ERROR 42818: Comparisons between 'LONG VARCHAR' and 'CHAR' are not supported