Subject | Re: [firebird-support] Re: 'when' conditions limits in case expression |
---|---|
Author | Mark Rotteveel |
Post date | 2012-03-07T11:43:41Z |
On Wed, 07 Mar 2012 11:34:09 -0000, "Cristiano" <boxferrari@...>
wrote:
value>? If so, consider using a helper-table and join against that instead
of using a CASE.
Mark
wrote:
> --- In firebird-support@yahoogroups.com, Thomas Steinmaurer <ts@...>wrote:
>> Is your question theoretical for some kind of case study or DBMSto,
>> comparison thingy or did you hit a limit already? Just curious. ;-)
>
> In really, is a practical question.
>
> I have to classify some records (about 300k) in many categories (nearly
> 200). So, I thought do this directly in the select statement (using case
> clause). However, write a query with 200 conditions "when ... then..."
> at the end, the debugger tell you that you reached the conditions limitsis
> kind annoying.Is it a straight forward WHEN field = <exact value> THEN <other exact
value>? If so, consider using a helper-table and join against that instead
of using a CASE.
Mark