Question

Table 1
Id Name Address


Table 2
Id Company Salary

Table3
Id Name Address Company Salary Age Sex

我想在单个MERGE语句中合并这些表，Is This 可能??

像

MERGE table1 AS tg1
MERGE table2 AS tg2
USING (SELECT Id ,Name ,Address FROM Table3) AS sr
ON tg1.Id = sr.Id and tg2.Id = sr.Id
WHEN MATCHED (tg1.Id =sr.Id) then DELETE
WHEN MATCHED (tg2.Id =sr.Id) then UPDATE SET tg2.Company = 'MyCompany'+sr.Company
and so on..

我是否需要为此类MERGE使用其他关键字声明，或者我需要use两个不同的MERGE声明此

Answer 1

Merge只能有一个目标表。

但你可以使用这样的东西：

DECLARE @T TABLE(Id INT);

MERGE table2 AS tg2
USING (SELECT Id, Name, Address, Company FROM Table3) AS sr
ON and tg2.Id = sr.Id
WHEN MATCHED THEN
    UPDATE SET tg2.Company = 'MyCompany' + sr.Company
OUTPUT tg2.Id INTO @T;

DELETE table1
WHERE Id in (SELECT Id
                 FROM @T);

OUTPUT也可以返回 $ action ，这样您就可以根据需要区分DELETE / INSERT / UPDATE。您甚至可以在MERGE之前使用CTE并准备源表以避免MERGE中的复杂条件。

Answer 2

您需要两个MERGE语句。一个用于更改table1中的数据，另一个用于更改table2中的数据。

具有2个以上表的SQL MERGE语句

2 个答案: