I have 2 mysql table: table t1: CREATE TABLE IF NOT EXISTS `t1` ( `id` bigint(20) NOT NULL, `url` varchar(255) DEFAULT NULL, `title` varchar(255) DEFAULT NULL, `type` varchar(255) DEFAULT ...
I saw in the documentation the difference between count(*) and count(pk). I had been using count(pk) (where pk is a SERIAL PRIMARY KEY) not knowing about the existence of count(*). My question is ...
Possible Duplicate: Storing vs calculating aggregate values Say I have a table full of photos that each have an albumId that is a foreign key to an album table. To get the amount of photos ...