SQL2008一行转多行的精典写法

--创建测试表
create table t1(    id int,    txt varchar(30))
--插入测试数据

insert into t1 select 1,'aa,dd,f' UNION
SELECT
  2,'ddd,ff,rt,gg'
union SELECT 
  3,'s,dddddee,d'
union SELECT
   4,'ty'  
union SELECT
   5,'hello,dderf,kii'
union SELECT
   6,'da,ddeff,ddd,d'


select * from t1  
--一行变多行的方法
select
a.id,b.txt
from
(select id,txt=convert(xml,'<root><v>'+replace(txt,',','</v><v>')+'</v></root>') from t1
)a
outer apply
(select txt=C.v.value('.','nvarchar(100)') from a.txt.nodes('/root/v')C(v))b