[mythtv] Joining on a calculated column

Chris Petersen lists at forevermore.net
Tue Jan 11 11:46:40 EST 2005


> AFAIK, yes. User functions are only in the MySQL 5.x development. With 
> MySQL 4.1, you could use a sub-select to create a virtual table with the 
> calculation done once. With 3.x and 4.0, I think you're stuck doing it 
> the long way.

Or you could create a temporary table in a separate query (as long as 
you have permission to do so).  Works nicely for some things, but beware 
of speed issues (mysql's optimizer might do this for your 
repeated-calculation thing, anyway).

-Chris


More information about the mythtv-dev mailing list