Hello, What is the best method to check if (one or more) row exists (note: primary key is auto inc and table engine is InnoDB - but what if these were not true) ?
1) SELECT * FROM <table> WHERE <condition> Check to see if the result set is non-empty. 2) SELECT COUNT(*) AS cnt FROM <table> WHERE <condition> Check to see if the field 'cnt' is non-zero. 3) SELECT <primary key> FROM <table> WHERE <condition> LIMIT 1 Check to see if the result set is non-empty. 4) SELECT 1 FROM <table> WHERE <condition> LIMIT 1 Check to see if the result set is non-empty. Any other possibilities? I hate (1) and don't mind the rest if PK is auto inc and table engine is InnoDB but I think (4) would be the best where PK is not auto inc and/or table engine is not InnoDB. Comments? Many thanks in advance, Nick -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
