sql server 字符串分割成列表

/*
功能：分割字符
示例：select * from split('aa,bb,cc,dd',',')
*/
CREATE FUNCTION [dbo].[split] (
    @String VARCHAR(MAX),--字符串
    @Delimiter VARCHAR(MAX)--需分割的字符
) 
RETURNS @temptable TABLE (items VARCHAR(MAX)) AS
BEGIN
    DECLARE @idx INT=1
    DECLARE @slice VARCHAR(MAX) 
    IF LEN(@String) < 1 OR LEN(ISNULL(@String,'')) = 0
        RETURN
    WHILE @idx != 0
    BEGIN
        SET @idx = CHARINDEX(@Delimiter,@String)
        IF @idx != 0
            SET @slice = LEFT(@String,@idx - 1)
        ELSE
            SET @slice = @String
        IF LEN(@slice) > 0
            INSERT INTO @temptable(items) VALUES(@slice)
        SET @String = RIGHT (@String, LEN(@String) - @idx)
        IF LEN(@String) = 0
            BREAK
    END
    RETURN
END