Seb wrote:
---<---------------cut here---------------start-------------->--- SELECT table1.col1 - table2.col1 AS diff1, table1.col2 + table2.col2 AS sum1, sum1 - diff1 FROM table1 INNER JOIN table2 ON (table1.id = table2.id) ---<---------------cut here---------------end---------------->---but this fails with the error message that sum1 column is not known. How can one get around this? The calculations are quite involved and would be difficult and error-prone to repeat them anywhere they're needed in the select list. Thanks in advance for any pointers.
The way I usually handle this is as follows. SELECT foo - bar AS baz FROM ( SELECT a.a + b.a AS foo, a.b + b.b AS bar FROM a JOIN b ON a.id = b.id ) AS subtable; Although, I'm not really sure that's The Right Way to do it. Colin -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
