SQL SERVER string into a function:

       Forum question: https://bbs.csdn.net/topics/392551043

       New method:

CREATE FUNCTION [dbo].Fn_GetStrTab (@str VARCHAR(100))
RETURNS @t TABLE (col NVARCHAR(200))
AS
BEGIN
    DECLARE @strlen INT;
    SELECT @strlen = LEN(@str);
    WHILE @strlen > 0
    BEGIN
        INSERT INTO @t
        (
            col
        )
        VALUES (SUBSTRING(@str, 1, 1));
        SET @str= STUFF(@str,1,1,'')   
        SET @strlen = LEN(@str);
    END;
    RETURN;
END;

       test:

SELECT * FROM dbo.Fn_GetStrTab(20190306)

       result: