首页 > 解决方案 > MySQL查询根据特定条件从多个表中选择

问题描述

我有两个表如下:

internetclient (id,full_name,location,phone_number)

internetclientdetails (incdid,icid,date_sub, date_exp,isPaid,profile_sub)

两个表中的数据如下: 客户端

--------------------------------------------------------
id         full_name       location    phone_number
-------------------------------------------------------
4         Joe Amine         beirut       03776132
5         Mariam zoue       beirut       03556133

客户订阅

--------------------------------------------------------------------------
incdid   icid      date_sub      date_exp      isPaid      sub_price
----------------------------------------------------------------------------
  6        4      2018-01-01     2018-01-30      0           2000
  7        5      2017-01-01     2017-01-30      0           1000
  8        4      2018-03-01     2018-03-30      1           50000
  9        5      2018-05-01     2019-05-30      1           90000

注意:incid 代表 internetClientDetailsId,icid 代表 internetClientId

问题 我想根据最新的客户订阅日期进行查询,返回客户名称以及所有详细信息,结果应如下所示:

------------------------------------------------------------
full_name     client_id     date_sub     sub_price
------------------------------------------------------------
 Joe Amine       4           2018-03-01      50000
 Mary            5           2018-05-01      90000

我在做什么

SELECT * FROM client c LEFT JOIN client_subscription c_s on c.id=c_s.client_id UNION SELECT * FROM client c RIGHT JOIN client_subscription c_S on c.id=c_s.client_id WHERE c.sub_date=(SELECT MAX(sub_date) from client_subscription c_s INNER JOIN client c on c.id=c_s.client_id GROUP BY c_s.client_id

我整晚都在努力。非常感谢任何帮助。

标签: mysqlselectjoinuniongreatest-n-per-group

解决方案


嗨,试试下面的示例可能会对您有所帮助。

DECLARE @tblClient AS TABLE (ID INT , Name varchar(100))
DECLARE @tblClientSub As TABLE (id INT,client_id INT,date_sub DATE,sub_price INT)

INSERT INTO @tblClient (id,Name)
VALUES 
(1,'Linda'),
(2,'Mary'),
(3,'Joe')  

INSERT INTO @tblClientSub(Id,client_id ,    date_sub ,    sub_price)
VALUES
(1,1,'2018/01/01',50),
(2,2,'2018/02/01',50),
(3,2,'2018/03/01',30),
(4,2,'2018/04/01',30),
(5,3,'2018/01/01',50),
(6,3,'2018/07/01',50),
(7,1,'2018/02/01',40)

SELECT c.Id,c.Name,cs.date_sub,cs.sub_price
FROM @tblClient c
CROSS APPLY (SELECT TOP (1)date_sub,sub_price 
             FROM @tblClientSub 
             WHERE client_id = c.Id 
             ORDER BY date_sub DESC) cs

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