[DERBY-4684] Correct the implicit casting of other types to BOOLEAN

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 10.6.1.0
• Fix Version/s: 10.7.1.1
• Component/s: SQL
• Bug behavior facts: Deviation from standard
• Assignee: Richard N. Hillegas
• Reporter: Richard N. Hillegas
• Created: 01/Jun/10 15:46
• Updated: 23/May/14 13:35
• Resolved: 03/Jun/10 16:11

Description

Via a UNION query, it is possible to implicitly cast non-BOOLEAN types to BOOLEAN today. These implicit casts do not obey the SQL Standard rules defined in part 2, section 6.12 (<cast specification>). Derby should support the Standard rules.

The following query shows how you can implicitly cast a non-BOOLEAN data type to BOOLEAN today:

select isindex from sys.sysconglomerates where conglomeratename = 'foo'
union
values ( 1 )

Issue Links

• is part of: DERBY-499 Expose BOOLEAN datatype to end users
• is related to: DERBY-6584 Comparisons between BOOLEAN and other types sometimes succeed
• is related to: DERBY-4692 Unions between BOOLEAN and non-BOOLEAN datatypes should be rejected