我想知道如何联合这么多SELECTS,以便得到1行不同列的结果.
SELECT COUNT(*) AS total_users FROM users;
SELECT COUNT(*) AS total_verified FROM users WHERE verified = 1;
SELECT COUNT(*) AS total_passed_tut FROM users WHERE level = 3;
SELECT COUNT(*) AS total_private FROM users WHERE privacy = 0;
SELECT COUNT(*) AS total_friends_only FROM users WHERE privacy = 2;
SELECT COUNT(*) AS total_public FROM users WHERE privacy = 3;
这样做有意义吗?或者我应该做单独的查询并保存到数组1?
解决方法:
SELECT COUNT(*) AS total_users,
sum(verified = 1) as total_verified,
sum(level = 3) as total_passed_tut,
sum(privacy = 0) as total_private,
sum(privacy = 2) as total_friends_only,
sum(privacy = 3) as total_public
FROM users;