Subject Re: [firebird-support] Re: 'when' conditions limits in case expression
Author Mark Rotteveel
On Wed, 07 Mar 2012 11:34:09 -0000, "Cristiano" <boxferrari@...>
> --- In, Thomas Steinmaurer <ts@...>
>> Is your question theoretical for some kind of case study or DBMS
>> 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 limits
> 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.