Question

我有一个table1，如下所示

user_ID country  status  role
-------- ------ ------- -----
keshav   SG        Active  Admin
Bargav   IN        Active  Subuser
Sanvi     GB       Active   subuser
yellin    CN       Active    subuser

我有另一个表stage_table，如下所示

user_ID  country   role 
-------  -------  ------
keshav     SG      Admin
Sanvi      GB      subuser
Manav      IN      subuser

我想基于stage_table更新table1。正如你所看到的，stage_table没有Bargav记录，所以我想更新table1 Bargav行，状态为＆＃34; InActive＆＃34;和Manav条目是新的，所以更新它，状态为＆＃34; Active＆＃34;。因此table1应如下所示

user_ID  country  status Role 
-------  -------  ------  -----
keshav   SG        Active  Admin
Bargav   IN        InActive  Subuser
Sanvi     GB       Active   subuser
yellin    CN       Active    subuser
Manav     In       Active    subuser

我正在考虑使用如下的内连接，这是正确的吗？我没有得到理想的结果..因为我不知道如何同时进行合并和更新

select * 
from table1 
inner join stage_table on table1.user_ID = stage_table.user_ID 
                       and (update table.status ="InActive" 
                            where table1.user_Id != stage_table.user_ID)

请帮忙。

Answer 1

MySQL / Mariadb和（我认为）SQLite将使用传统的SQL结构，如下所示，您需要将插入和更新作为单独的查询进行：

INSERT INTO table1 (user_ID, country, status, role)
SELECT t2.user_ID, t2.country,'Active' as Status, t2.role 
FROM table2 t2
LEFT JOIN table1 t1 ON t1.user_id = t2.user_id
WHERE t1.user_id IS NULL
;

UPDATE  table1 t1
LEFT JOIN table2 t2 ON t1.user_id = t2.user_id
SET t1.status = CASE WHEN t2.user_id IS NULL THEN 'InActive' ELSE 'Active' END
;

Answer 2

在MS SQL Server中，您可以分别使用以下两个查询进行更新和插入 -

-- For Update
UPDATE T1
SET T1.[STATUS] = (
    CASE 
        WHEN T2.[USER_ID] IS NULL
            THEN 'INACTIVE'
        ELSE T1.[STATUS]
        END
    )
FROM TABLE1 T1
LEFT OUTER JOIN STAGE_TABLE T2 ON T1.[USER_ID] = T2.[USER_ID];

-- For Insert
INSERT INTO TABLE1 (
    [USER_ID]
    ,COUNTRY
    ,[STATUS]
    ,[ROLE]
    )
SELECT T2.[USER_ID]
    ,T2.COUNTRY
    ,'Active'
    ,T2.[ROLE]
FROM TABLE1 T1
RIGHT OUTER JOIN STAGE_TABLE T2 ON T1.[USER_ID] = T2.[USER_ID]
WHERE T1.[USER_ID] IS NULL;

内部联接和更新

2 个答案: