Question

我可以在SQL Sever中使用多个CTE INSERT表达式吗？

这在PostgreSQL中是允许的：

writeable common table expression and multiple insert statements

例如在PostgreSQL中。

with foo as 
(
      select * from ...
),
b as 
(
      insert into bar
          select * from foo
          returning *
)
insert into baz
    select * from foo;

我在SQL Server中尝试过：

;WITH cte1 AS 
(
    SELECT * FROM Foo       
),
cte2 AS ( -- depends on cte1
    SELECT * FROM Bar WHERE ID IN (SELECT ID FROM cte1)
),
cte3 AS ( -- first insert
    INSERT INTO Baz1
    OUTPUT INSERTED.*
    SELECT * FROM cte2
)
INSERT INTO Baz2 -- second insert depends on ct3 data-set
SELECT * FROM cte3

以上不起作用。

Answer 1

对于您的情况，我会考虑在MS SQL Server中使用trigger（以及它可以访问的inserted临时表）-可以找到更多信息{{3 }}。另一个有用的链接here。

我如何处理您的问题是将其视为两个单独的代码块：

第一个块（从两个CTE运行第一个插入语句）：

;WITH cte1 AS 
(
    SELECT * FROM Foo       
),
cte2 AS ( -- depends on cte1
    SELECT * FROM Bar WHERE ID IN (SELECT ID FROM cte1)
)
INSERT INTO Baz1
SELECT * 
FROM cte2

第二个块（Baz1表中存在的触发器，在对该表执行INSERT之后运行）：

CREATE TRIGGER [Some_unique_trigger_name] ON Baz1
AFTER INSERT
AS
BEGIN
    SET NOCOUNT ON;
    INSERT INTO Baz2(
        column_names
    )
    SELECT *
    FROM inserted i
END

您必须首先更新查询以使其与列名/表名/触发器名等匹配。

带有多个插入语句的SQL Server CTE

1 个答案: