Maybe you think about WITH queries? 2011/4/17, Robert J.C. Ivens <rob...@roclasi.com>: > > On 17 apr 2011, at 13:21, Leif Biberg Kristensen wrote: > >> On Sunday 17 April 2011 13:01:45 Robert J.C. Ivens wrote: >>> Hi, >>> >>> I am not sure if there ever was a feature request for using defined >>> column >>> aliases in the rest of a query. This would make queries with a lot of >>> logic in those aliased columns a lot smaller and this easier to >>> write/debug. >>> >>> I already know you can use the following syntax: >>> >>> SELECT col1, col2, col3, (col2-col3) as col4 FROM (SELECT col1, (long and >>> lots of logic here) as col2, col3 FROM table) s WHERE col2 < aValue >>> >>> But when you need to use (calculated) values from the actual record and >>> or >>> have sub-selects in your main select that also need to use these values >>> things get really hairy. I don't know if the SQL specification allows it >>> but I know that RDBMS's like Sybase already support this. >>> >>> Any thoughts? >> >> It's easy to define a view or an SQL function and stash the hairy logic >> there. >> >> regards, Leif > > True, but that is essentially the same thing as the example query I gave. > There are plenty of cases where this approach is not workable. > > Cheers, > Robert > > > -- > Sent via pgsql-general mailing list (pgsql-general@postgresql.org) > To make changes to your subscription: > http://www.postgresql.org/mailpref/pgsql-general >
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