From: "Gustavo Andrade" > select count(distinct membros.ID) as total_membros, count(distinct > replays.ID) as total_replays, count(distinct downloads.ID) as > total_downloads from membros,replays,downloads;
Why join three tables to count the records in each one? I'm sure the performance will be poor once you get more data. > if one of the tables have 0 records all the counts will turn to 0 > the count works only if all the tables have records > how can i fix that? By joining the tables you are asking for all possible combinations of the rows (cartesian product). The number of rows obtained is: (n. rows in table 1) * (n. rows in table 2) * ( n. rows in table 3) So if a table has 0 rows there are 0 possible combinations. For this reason and also for performance reasons, you should do 3 separate selects. If ID is a unique key, you can also take out the distinct, which in your query you needed because by making all possible combinations you repeated the same ID many times. John _________________________________________________ Quer ter um fórum para seu clan de Starcraft/BroodWar, Counter-Strike, Warcraft ou outros. entre em http://www.arena-star.com.br/forum/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
