zoukankan      html  css  js  c++  java
  • MSSQL列记录合并

    创建表及插入数据

    If OBJECT_ID(N'Demo') Is Not Null
        Begin
            Drop Table Demo
        End
    Else
        Begin
            Create Table Demo(
            Area nvarchar(30),
            Name nvarchar(20))
    
            Insert Into Demo(Area,Name)
            Values(N'北京',N'张三'),
            (N'上海',N'李四'),
            (N'深圳',N'王五'),
            (N'深圳',N'钱六'),
            (N'北京',N'赵七'),
            (N'北京','Tom'),
            (N'上海','Amy'),
            (N'北京','Joe'),
            (N'深圳','Leo')
        End
    Go
    SELECT ','+Name FROM dbo.Demo FOR XML PATH('')
    
    Declare @NameCollection nvarchar(500)
    Select @NameCollection=ISNULL(@NameCollection+',','')+Name From dbo.Demo
    Select @NameCollection as NameCollection

    SELECT  Area,
    (SELECT ','+Name FROM dbo.Demo WHERE Area = t.Area FOR XML PATH(''))
    AS NameCollection FROM dbo.Demo AS t
    
    SELECT Area,
    STUFF((SELECT ','+Name FROM dbo.Demo WHERE Area = t.Area FOR XML PATH('')),1,1,'')
    AS NameCollection FROM dbo.Demo AS t

    建一个函数,传入一个Area参数,根据Area来进行合并,返回合并值

    CREATE FUNCTION MergeByColumn 
    (
        -- Add the parameters for the function here
        @Area nvarchar(30)
    )
    RETURNS nvarchar(500)
    AS
    BEGIN
        -- Declare the return variable here
        DECLARE @NC nvarchar(500)  
    
        -- Add the T-SQL statements to compute the return value here
        SELECT @NC=ISNULL(@NC+',','')+Name FROM dbo.Demo WHERE Area=@Area
    
        -- Return the result of the function
        RETURN @NC
    
    END
    GO
    SELECT DISTINCT Area,dbo.MergeByColumn(Area) AS NameCollection From dbo.Demo
    
    SELECT Area,dbo.MergeByColumn(Area) AS NameCollection From dbo.Demo GROUP BY Area

  • 相关阅读:
    CRB and His Birthday(2015多校)
    B. Bear and Three Musketeers
    Uva657
    cas服务端改造
    有用的maven插件
    maven管理的非标准目录
    struts2中的action交由spring管理
    数据库分库
    linux内核系列之二_资源
    linux内核系列之一_工具
  • 原文地址:https://www.cnblogs.com/Snowfun/p/5053002.html
Copyright © 2011-2022 走看看