仅选择/计数已验证且未禁止的用户

Question

这是代码

SELECT username,count(username) FROM users WHERE status = '1' // $vuser to get the verified user only (it's the main query)

SELECT username FROM banned_users WHERE username = $vuser  // if yes $bad_user is true else false

是否可以使用一个 sql 查询仅选择/计算在banned_users中不存在的已验证用户？

有什么想法吗？

Answer 1

SELECT u.username, count(u.username) 
FROM users u
left outer join banned_users b on b.username = u.username
WHERE u.status = '1'
AND b.username is null
GROUP BY u.username