Hi "MySQL", > I record some stock data into MySQL, I'm looking for the correct > syntax for a SELECT statement. > > SELECT min(Tmin) FROM quotes WHERE low=min(low) > > In short, I want the time of the occurance of the low for the day, > Tmin is time column. Once the low is achieved, all the remaining data > for the day has the same low recorded, so I want the first occurance. > > I tried > > SELECT min(tmin) FROM quotes WHERE tag='CSCO' HAVING min(low); > > which at least didn't have syntax errors, but alas did not produce a > result.
MIN() etc are group functions, so it is difficult to compare them with (scalar) values from individual rows - hence the failure of the first attempt. The second attempt is missing the intended comparison in the HAVING clause, so the MIN() result is interpreted as boolean and 'this dog don't hunt, Wilbur!'. I'm a little confused about the ambiguities of the MIN( tmin ) in the SELECT clause - perhaps you should post your table schema - if this is relevant. Using a test table I happened to have 'lying around', would this approach fit the bill? SELECT id, type_id, product_id FROM attribute WHERE type_id = 2 HAVING min( product_id ) = product_id; Regards, =dn --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
