函数TSQL中的函数 [英] Function within a Function TSQL

问题描述

我可以在表值函数中调用标量函数吗？

谢谢 是的，只要table-

用户定义的函数可以嵌套;
即一个用户定义的函数可以
调用另一个函数。当被调用的函数
开始执行时，嵌套级别为
，当
被调用的函数完成
执行时，该级别递减。用户定义的函数可以
嵌套到32个级别。超过
嵌套的最大级别导致
整个调用函数链到
失败。从Transact-SQL用户定义的
函数对托管代码
的任何引用都将作为一个级别对
的32级嵌套限制进行计数。方法在托管代码中调用

不计入此限制。

http://msdn.microsoft.com/en-us/library/ms186755.aspx

这非常简单，但它确实有效：

   - DROP FUNCTION RETURN_INT 
 --GO 
 CREATE FUNCTION RETURN_INT（）
 RETURNS INT 
 WITH EXECUTE AS CALLER 
 AS 
 BEGIN 
 RETURN 1 
 END 
 
 GO 
 
 --DROP FUNCTION RETURN_TABLE 
 --GO 
 CREATE FUNCTION RETURN_TABLE（）
 RETURNS @Test TABLE （
 ID INT 
）
执行呼叫者
 AS 
 BEGIN 
 
 INSERT INTO @Test 
 SELECT DBO.RETURN_INT （）
 RETURN 
 END 
  

Can I call a scalar function within a table-valued function?

Thanks

解决方案

Yes, just as long as the table-valued function returns a table when it's done.

User-defined functions can be nested; that is, one user-defined function can call another. The nesting level is incremented when the called function starts execution, and decremented when the called function finishes execution. User-defined functions can be nested up to 32 levels. Exceeding the maximum levels of nesting causes the whole calling function chain to fail. Any reference to managed code from a Transact-SQL user-defined function counts as one level against the 32-level nesting limit. Methods invoked from within managed code do not count against this limit.

http://msdn.microsoft.com/en-us/library/ms186755.aspx

This is very simplistic, but it does work:

--DROP FUNCTION RETURN_INT
--GO
CREATE FUNCTION RETURN_INT ()
    RETURNS INT
WITH EXECUTE AS CALLER
AS
BEGIN
    RETURN 1
END

GO

--DROP FUNCTION RETURN_TABLE
--GO
CREATE FUNCTION RETURN_TABLE ()
    RETURNS @Test TABLE (
    ID INT 
)
WITH EXECUTE AS CALLER
AS 
BEGIN

INSERT INTO @Test
    SELECT DBO.RETURN_INT()
RETURN 
END

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