Hi, I have a SELECT statement that is a bit involved in terms of calculations, so I wanted to set up some column aliases and refer to them further down the select list: ---<---------------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. Cheers, -- Seb