Re: LEFT JOIN not working

OK, this helped a bit. Now I have, in addition to the three rows of ads that have ben clicked on, a fourth row with no ad name, 0 clickthroughs, and 24 displays. That plus the other three account for all the displayed ads. However, since it is returning a null value for any ad name that has not been clicked on, and then it's grouped by ad name, it lumps all non-clicked ads into one row. What I need is to see each ad on a separate row, which is what I thought a LEFT JOIN was supposed to do. Any suggestions? Thanks, -Lisi At 11:07 AM 1/9/03 +0100, Ignatius Reilly wrote:

problem 1: move the WHERE clauses to the ON clauses problem 2: Obviously your intent with " COUNT(ads_clickrate.date) " is to count the number of non-null occurences of click. But COUNT() is not the appropriate function to do this (it will simply give you the number of rows inside a group). Try replacing COUNT(ads_clickrate.date) by SUM( IF( ads_clickrate.date IS NULL, 0, 1 ) ) HTH Ignatius ____________________________________________ ----- Original Message ----- From: "Lisi" <lists@shemeshdirectory.co.il> To: "PHP-DB" <php-db@lists.php.net> Sent: Thursday, January 09, 2003 10:44 AM Subject: [PHP-DB] LEFT JOIN not working I have a page with many ads that stores both the number of times an ad is displayed and how many times it gets clicked. These are stored in two different tables (since different information is stored for each) but both have identical name columns. I am trying to display both # times displayed and # times clicked in the same table in an admin page. Here is my query: SELECT ads_clickrate.name, ads_clickrate.link, SUM(ads_displayrate.count) as display, COUNT(ads_clickrate.date) as click FROM ads_displayrate LEFT JOIN ads_clickrate ON ads_displayrate.name = ads_clickrate.name WHERE YEAR(ads_clickrate.date) = '2003' AND MONTH(ads_clickrate.date) = '01' GROUP BY ads_clickrate.name ORDER BY ads_clickrate.name I want to display for each ad the number of times displayed, and then number of times clicked if applicable, if not 0. The query is only returning rows for ads that have been clicked on. Is the problem because I have a COUNT column for one table, with a group by? Is this causing the display to be grouped also? If you need more information how the table is set up let me know, I'm really stumped here. Thanks, -Lisi -- PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php