<p>13.7 练习</p>

1. 将第12章中的spTriangular存储过程重新实现为函数。

先看看第12章中的spTriangular存储过程的定义与用法示例。

定义：

CREATE PROC spTriangular
	@ValueIn int,
	@ValueOut int OUTPUT
AS
	DECLARE @InWorking int;
	DECLARE @OutWorking int;

IF @ValueIn != 1
BEGIN
	SELECT @InWorking = @ValueIn - 1;
	EXEC spTriangular @InWorking, @OutWorking OUTPUT;
	SELECT @ValueOut = @ValueIn + @OutWorking;
END
ELSE
BEGIN
	SELECT @ValueOut = 1;
END
RETURN;



GO

调用示例：

DECLARE @WorkingOut int;
DECLARE @WorkingIn int;
SELECT @WorkingIn = 5;
EXEC spTriangular @WorkingIn, @WorkingOut OUTPUT;

PRINT CAST(@WorkingIn AS varchar) + ' Triangular is ' + CAST(@WorkingOut AS varchar);

现在将存储过程spTriangular实现为函数如下：

CREATE FUNCTION dbo.fnTriangular(@ValueIn int)
RETURNS int
AS
BEGIN
	DECLARE @ReturnValue int;

IF @ValueIn &gt; 1 
BEGIN
	SELECT @ReturnValue = @ValueIn + dbo.fnTriangular(@ValueIn - 1);
END
ELSE
BEGIN
	SET @ReturnValue = 1
END
RETURN @ReturnValue



END

调用示例：

SELECT dbo.fnTriangular(5)