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From Daniel John Debrunner <...@apache.org>
Subject Collation derivation for UPPER etc. incorrect in wiki page?
Date Tue, 04 Sep 2007 18:48:20 GMT
Rule 5) in the collation wiki page says:
-------------------------------------------------------------------
5)Result character string types from UPPER, LOWER, TRIM(LTRIM, RTRIM), 
SUBSTR will have the same collation as their operand. This comes from 
SQL spec Section 6.29 <string value function> Syntax Rules 8, 8, 11d, 4 
respectively). The collation derivation will be implicit.
-------------------------------------------------------------------

http://wiki.apache.org/db-derby/BuiltInLanguageBasedOrderingDERBY-1478

I don't see where the last sentence comes from: "The collation 
derivation will be implicit.".

That doesn't seem to be correct, if the operand has collation explicit 
or none shouldn't that be carried through to the result of the character 
string function? The rules in 6.29 that are quoted by 5) above just say 
the type is the type of the operand which includes the derivation, 
right? I don't see anything in 6.29 about asserting implicit derivation.

I haven't looked at the code to see what is implemented, just wanted to 
raise this as a possible issue.

Dan.

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