[DERBY-2866] Improve error message when comparing user table and system table columns if collation doesn't match

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Duplicate
• Affects Version/s: 10.3.1.4
• Component/s: SQL
• Assignee: Unassigned
• Reporter: Katherine Marsden
• Created: 22/Jun/07 22:47
• Updated: 26/Jun/07 19:53
• Resolved: 26/Jun/07 19:52

Description

If I create a database with TERRITORY_BASED collation and try to do a comparison between a user table column and a system table column, I get the following message. If I create it with UCS_BASIC collation there is no problem with the query. It makes sense to me that I can't compare these columns but I think it would be worthwhile to make a more informative error message since in fact normally comparisons between VARCHAR and VARCHAR are supported, just not comparisons between TERRITORY_BASED and UCS_BASIC.

Kathey

ij> connect 'jdbc:derby:enusdb;create=true;territory=en_US;collation=TERRITORY_BASED';
ij(CONNECTION1)> create table t (vc varchar(30));
0 rows inserted/updated/deleted
ij(CONNECTION1)> insert into t values('t');
1 row inserted/updated/deleted
ij(CONNECTION1)> select tableName, vc from sys.systables, t where vc = tableName;
ERROR 42818: Comparisons between 'VARCHAR' and 'VARCHAR' are not supported.

Bryan suggests ...

Can we make it say something like:

ERROR 42818: Comparisons between 'VARCHAR(en_US)' and 'VARCHAR(UCS_BASIC)' are not supported.

That is, sort of pack the collation information into the datatype
name somehow?

Issue Links

• duplicates: DERBY-2668 At the time of compilation of a comparison operation, if the collation types of the operands do not match, then we should throw a meaningful error message.
• is related to: DERBY-1478 Add built in language based ordering and like processing to Derby