sql函数将1，2，3转换为表

/****** Object:  UserDefinedFunction [dbo].[splitstring_to_table]    Script Date: 2017/7/11 9:35:58 ******/
SET ANSI_NULLS ON
GO

SET QUOTED_IDENTIFIER ON
GO

ALTER FUNCTION [dbo].[splitstring_to_table]
(
    @string NVARCHAR(MAX),--需要分割的支付如： ‘1，2，3，4’
    @delimiter CHAR()--分隔的字符串 ‘，’
)
RETURNS @output TABLE(
    data NVARCHAR(MAX)
)
BEGIN
    DECLARE @start INT, @end INT
    SELECT @start = , @end = CHARINDEX(@delimiter, @string)

    WHILE @start < LEN(@string) +  BEGIN
        IF @end =
            SET @end = LEN(@string) + 

        INSERT INTO @output (data)
        VALUES(SUBSTRING(@string, @start, @end - @start))
        SET @start = @end +
        SET @end = CHARINDEX(@delimiter, @string, @start)
    END
    RETURN
END

GO