[
https://issues.apache.org/jira/browse/DERBY-6584?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14007201#comment-14007201
]
Knut Anders Hatlen commented on DERBY-6584:
-------------------------------------------
Thanks, Rick. That part of the standard says you can cast between BOOLEAN and
character types. So now we need to figure out if that's enough to make them
comparable.
Right now, I'm trying to break out of an infinite loop following a circular
definition of "comparable":
3.1.6.5 "comparable (of a pair of values)" says: capable of being compared,
according to the rules of Subclause 8.2, “<comparison predicate>”
8.2 "<comparison predicate>", SR 3, says: The declared types of the
corresponding fields of the two <row value predicand>s shall be comparable.
> Comparisons between BOOLEAN and other types sometimes succeed
> -------------------------------------------------------------
>
> Key: DERBY-6584
> URL: https://issues.apache.org/jira/browse/DERBY-6584
> Project: Derby
> Issue Type: Bug
> Components: SQL
> Affects Versions: 10.10.2.0
> Reporter: Knut Anders Hatlen
>
> I would have expected the following queries to fail because of type mismatch
> between CHAR and BOOLEAN:
> {noformat}
> ij> values 'abc' = true, true = 'xyz', false = 'yes';
> 1
> -----
> true
> true
> false
> 3 rows selected
> ij> values 'abc' in (true, false), true in ('abc', 'def');
> 1
> -----
> true
> true
> 2 rows selected
> {noformat}
> Similar queries using INTEGER values instead of CHAR values fail as expected:
> {noformat}
> ij> values 1 = true;
> ERROR 42818: Comparisons between 'INTEGER' and 'BOOLEAN' are not supported.
> Types must be comparable. String types must also have matching collation. If
> collation does not match, a possible solution is to cast operands to force
> them to the default collation (e.g. SELECT tablename FROM sys.systables WHERE
> CAST(tablename AS VARCHAR(128)) = 'T1')
> ij> values true = 1;
> ERROR 42818: Comparisons between 'BOOLEAN' and 'INTEGER' are not supported.
> Types must be comparable. String types must also have matching collation. If
> collation does not match, a possible solution is to cast operands to force
> them to the default collation (e.g. SELECT tablename FROM sys.systables WHERE
> CAST(tablename AS VARCHAR(128)) = 'T1')
> ij> values true in (1,2,3);
> ERROR 42818: Comparisons between 'BOOLEAN' and 'INTEGER' are not supported.
> Types must be comparable. String types must also have matching collation. If
> collation does not match, a possible solution is to cast operands to force
> them to the default collation (e.g. SELECT tablename FROM sys.systables WHERE
> CAST(tablename AS VARCHAR(128)) = 'T1')
> ij> values 1 in (true, false);
> ERROR 42818: Comparisons between 'INTEGER' and 'BOOLEAN' are not supported.
> Types must be comparable. String types must also have matching collation. If
> collation does not match, a possible solution is to cast operands to force
> them to the default collation (e.g. SELECT tablename FROM sys.systables WHERE
> CAST(tablename AS VARCHAR(128)) = 'T1')
> {noformat}
--
This message was sent by Atlassian JIRA
(v6.2#6252)
