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
