Re: sql

On Monday 25 October 2004 05:20, Mike Rylander wrote:
> SELECT * FROM temp50 GROUP BY gc ORDER BY ora DESC;

You can not have have expressions (columns etc.) in the SELECT list that are 
either not in a GROUP BY clause, or used in an aggregate function when you 
use GROUP BY in the statement.  By saying SELECT *, means you would have to 
GROUP BY gc, co, data, ora ...

That isn't going to do what he wants.  And the SQL you stated should give you 
an error:

ERROR:  column "temp50.co" must appear in the GROUP BY clause or be used in an 
aggregate function



What he wants to do is use DISTINCT ON:

SELECT DISTINCT ON (gc) gc, co, data, ora FROM temp50 ORDER BY gc, ora DESC;


Andy