三个不同 mysql 查询表的连接

Question

嘿，我是 php 和 mysql 的新手。这里想加入三个不同的要求。 这是我的疑问

查询1：

SELECT u.user_name,u.first_name 
FROM users u join users_cstm uc on u.id=uc.id_c 
WHERE u.deleted=0?

查询2：

SELECT l.assigned_user_id,count(*) AS lead_count 
FROM lead l GROUP BY l.assigned_user_id?

查询3：

SELECT l.assigned_user_id,AVG(DATEDIFF(l.date_modified,l.date_entered)) AS avgdays 
FROM leads l GROUP BY l.assigned_user_id?

等等..关于..

这是我正在寻找的结果 user_name、first_name、lead_count、avgdays。来自三个表。

BigQuery join of three tables

我已经从上面的链接尝试了我的解决方案。但我没有得到结果？

感谢您的帮助和建议。

Answer 1

试试下面的查询：-

SELECT u.user_name,u.first_name,
lead_table.lead_count,lead_table.avgdays
FROM users u join users_cstm uc on u.id=uc.id_c
left join 
(SELECT l.assigned_user_id,
        AVG(l.date_modified) AS avgdays,
        count(*) AS lead_count 
FROM leads l GROUP BY l.assigned_user_id) lead_table
on u.id=lead_table.assigned_user_id
WHERE u.deleted=0;

Answer 2

试试这个：

SELECT id,user_name,first_name,lead_count,avgdays from
(SELECT id,user_name,first_name,lead_count from
(SELECT u.id,u.user_name,u.first_name FROM users u,users_cstm uc where  u.id=uc.id_c and u.deleted=0) as a

LEFT JOIN

(SELECT l.assigned_user_id,count(*) AS lead_count FROM lead l GROUP BY l.assigned_user_id) as b
on a.id = b.assigned_user_id) as a

LEFT JOIN 

(SELECT l.assigned_user_id,AVG(DATEDIFF(l.date_modified,l.date_entered)) AS avgdays 
FROM leads l GROUP BY l.assigned_user_id) as b
on a.id = b.assigned_user_id