表中某字段按分隔符拆分为多行

DECLARE @TB AS TABLE (C1 INT,C2 VARCHAR(20),C3 VARCHAR(200))

INSERT INTO @TB(C1,C2,C3)

SELECT 1 AS C1,'A','a,b,c'

UNION 

SELECT 2,'A','a,b'

UNION 

SELECT 3,'B','a,b'

UNION 

SELECT 4,'C','a,b'



SELECT * FROM @TB



C1          C2                   C3

----------- -------------------- --------------------

1           A                    a,b,c

2           A                    a,b

3           B                    a,b

4           C                    a,b





想实现结果为：





C1          C2                   C3

----------- -------------------- --------------------

1           A                    a

1           A                    b

1           A                    c

2           A                    a

2           A                    b

3           B                    a

3           B                    b

4           C                    a

4           C                    b