我有3个表:问题与SQL加盟
我有这个到目前为止已经试过:
SELECT T1.P_id as id, T2.D_id, COALESCE(T2.count , 0) AS count
FROM
(
SELECT DISTINCT P_id FROM Comp_prod WHERE company_id = '15'
) AS T1
LEFT JOIN
(
SELECT D_id, P_id, COUNT(P_id) AS count
FROM userlogs
WHERE company_id = '15'
AND date BETWEEN 'daterstart' AND 'dateend'
GROUP BY D_id, P_id
) AS T2 ON T2.P_id = T1.P_id
这是行不通的,因为我需要连接到另一个表:
部门
我怎样才能有另一个子查询?
任何解决方案?它的MySQL我使用
这个查询有问题,给出错误。我似乎无法弄清楚 –
有什么错误? [链接](http://sqlfiddle.com/#!9/4791d/1) –
它终于奏效了!条件很少,但效果很好。谢谢 –