分拆列值

分拆列值

原著：鄒建
改編：愛新覺羅.毓華(十八年風雨,守得冰山雪蓮花開)  2007-12-16  廣東深圳

有表tb, 如下:
id          value
----------- -----------
1           aa,bb
2           aaa,bbb,ccc
欲按id,分拆value列, 分拆後結果如下:
id          value
----------- --------
1           aa
1           bb
2           aaa
2           bbb
2           ccc

1. 舊的解決方法(sql server 2000)
SELECT TOP 8000 id = IDENTITY(int, 1, 1) INTO # FROM syscolumns a, syscolumns b 

SELECT A.id, SUBSTRING(A.[values], B.id, CHARINDEX(',', A.[values] + ',', B.id) - B.id)
FROM tb A, # B
WHERE SUBSTRING(',' + A.[values], B.id, 1) = ','

DROP TABLE #

2. 新的解決方法(sql server 2005) 

create table tb(id int,value varchar(30))
insert into tb values(1,'aa,bb')
insert into tb values(2,'aaa,bbb,ccc')
go
SELECT A.id, B.value
FROM(
    SELECT id, [value] = CONVERT(xml,'<root><v>' + REPLACE([value], ',', '</v><v>') + '</v></root>') FROM tb
)A
OUTER APPLY(
    SELECT value = N.v.value('.', 'varchar(100)') FROM A.[value].nodes('/root/v') N(v)
)B

DROP TABLE tb

/*
id          value
----------- ------------------------------
1           aa
1           bb
2           aaa
2           bbb
2           ccc

(5 行受影響)
*/