• SQLServer 简单数据拆分


    -1. 旧的解决方法(sql server 2000)

     
    create table tb(id int,value varchar(30))
    insert into tb values(1,'aa,bb')
    insert into tb values(2,'aaa,bbb,ccc')
    go
     
    --方法1.使用临时表完成
    SELECT TOP 8000 id = IDENTITY(int, 1, 1) INTO # FROM syscolumns a, syscolumns b 
     
    SELECT A.id, value = SUBSTRING(A.[value], B.id, CHARINDEX(',', A.[value] + ',', B.id) - B.id)
    FROM tb A, # B
    WHERE SUBSTRING(',' + A.[value], B.id, 1) = ','
     
    DROP TABLE #
     
    --方法2.如果数据量小,可不使用临时表
    select a.id , value = substring(a.value , b.number , charindex(',' , a.value + ',' , b.number) - b.number) 
    from tb a join master..spt_values  b 
    on b.type='p' and b.number between 1 and len(a.value)
    where substring(',' + a.value , b.number , 1) = ','
     
    --2. 新的解决方法(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
     
    --方法1.使用xml完成
    SELECT A.id, B.value FROM
    (
      SELECT id, [value] = CONVERT(xml,'' + REPLACE([value], ',', '') + '') FROM tb
    ) A OUTER APPLY
    (
      SELECT value = N.v.value('.', 'varchar(100)') FROM A.[value].nodes('/root/v') N(v)
    ) B
     
    --方法2.使用CTE完成
    ;with tt as 
    (select id,[value]=cast(left([value],charindex(',',[value]+',')-1) as nvarchar(100)),Split=cast(stuff([value]+',',1,charindex(',',[value]+','),'') as nvarchar(100)) from tb
    union all
    select id,[value]=cast(left(Split,charindex(',',Split)-1) as nvarchar(100)),Split= cast(stuff(Split,1,charindex(',',Split),'') as nvarchar(100)) from tt where split>''
    )
    select id,[value] from tt order by id option (MAXRECURSION 0)
     
     
    DROP TABLE tb
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  • 原文地址:https://www.cnblogs.com/lydg/p/11362555.html
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