• 常用SQL收藏


    MSSQL Split表字段

    --拆分字符串之后匹配结果集合
    CREATE FUNCTION [dbo].[fnSplit](
        @sInputList VARCHAR(8000) -- List of delimited items
      , @sDelimiter VARCHAR(8000) = ',' -- delimiter that separates items
    ) RETURNS @List TABLE (item VARCHAR(8000))
    
    BEGIN
    DECLARE @sItem VARCHAR(8000)
    WHILE CHARINDEX(@sDelimiter,@sInputList,0) <> 0
     BEGIN
     SELECT
      @sItem=RTRIM(LTRIM(SUBSTRING(@sInputList,1,CHARINDEX(@sDelimiter,@sInputList,0)-1))),
      @sInputList=RTRIM(LTRIM(SUBSTRING(@sInputList,CHARINDEX(@sDelimiter,@sInputList,0)+LEN(@sDelimiter),LEN(@sInputList))))
     
     IF LEN(@sItem) > 0
      INSERT INTO @List SELECT @sItem
     END
    
    IF LEN(@sInputList) > 0
     INSERT INTO @List SELECT @sInputList -- Put the last item in
    RETURN
    END
    
    ----------------------使用方法
    if   object_id('tempdb..#Tmp') is not null   
            drop table #Tmp
    create table #Tmp --创建临时表#Tmp
    (
        ID   VARCHAR(100)  
    );
    
    DECLARE @iid VARCHAR(100)
    declare @name varchar(500)
    declare cursor1 cursor for         --定义游标cursor1
    select iid,props from Iteminfos               --使用游标的对象
    open cursor1                       --打开游标
    
    fetch next from cursor1 into @iid,@name  --将游标向下移1行,获取的数据放入之前定义的变量@iid,@name中
    
    while @@fetch_status=0           --判断是否成功获取数据
    begin
    IF((select COUNT(*) FROM fnSplit(@name, ';') WHERE  item = '20000:20090')>0)
    INSERT INTO #Tmp (ID) VALUES (@iid)
    fetch next from cursor1 into @iid,@name  --将游标向下移1行
    end
    
    close cursor1                   --关闭游标
    deallocate cursor1
    
    SELECT * FROM dbo.Iteminfos WHERE iid IN( SELECT ID FROM #Tmp)
    

    查询节点的函数

    create table tb(id varchar(3) , pid varchar(3) , name varchar(10))
    insert into tb values('001' , null , '广东省')
    insert into tb values('002' , '001' , '广州市')
    insert into tb values('003' , '001' , '深圳市')
    insert into tb values('004' , '002' , '天河区')
    insert into tb values('005' , '003' , '罗湖区')
    insert into tb values('006' , '003' , '福田区')
    insert into tb values('007' , '003' , '宝安区')
    insert into tb values('008' , '007' , '西乡镇')
    insert into tb values('009' , '007' , '龙华镇')
    insert into tb values('010' , '007' , '松岗镇')
    go
    -------------创建方法
    create function f_cid(@ID varchar(3)) returns @t_level table(id varchar(3) , level int)
    as
    begin
    declare @level int
    set @level = 1
    insert into @t_level select @id , @level
    while @@ROWCOUNT > 0
    begin
    set @level = @level + 1
    insert into @t_level select a.id , @level
    from tb a , @t_Level b
    where a.pid = b.id and b.level = @level - 1
    end
    return
    END
    GO
    --------------使用方法
    select a.* from tb a , f_cid('001') b where a.id = b.id order by a.id
    --------------调用函数查询(广州市)及其所有子节点
    select a.* from tb a , f_cid('002') b where a.id = b.id order by a.id
    

    Exists,Datediff,Newid,

    ---两张关联表,删除主表中已经在副表中没有的信息 
    delete from table1 where not exists ( select * from table2 where table1.field1=table2.field1 )
    
    ---日程安排提前五分钟提醒 
    SQL: select * from 日程安排 where datediff('minute',f开始时间,getdate())>5
    
    ---随机取出10条数据
    select top 10 * from tablename order by newid()
    
    -- 类似有 month day year
    select * from table1   where convert(varchar,date,120) like   '2006-04-01%'  
    --datediff
    select * from table1   where datediff(day,time,'2006-4-1')=0

    删除重复值

    --1、查找表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断   
    select   *   from   people   
    where   peopleId   in   (select     peopleId     from     people     group     by     peopleId     having     count(peopleId)   >   1)   
        
    --2、删除表中多余的重复记录,重复记录是根据单个字段(peopleId)来判断,只留有rowid最小的记录   
    delete   from   people     
    where   peopleId     in   (select     peopleId     from   people     group     by     peopleId       having     count(peopleId)   >   1)   
    and   rowid   not   in   (select   min(rowid)   from     people     group   by   peopleId     having   count(peopleId   )>1)   
        
    --3、查找表中多余的重复记录(多个字段)     
    select   *   from   vitae   a   
    where   (a.peopleId,a.seq)   in     (select   peopleId,seq   from   vitae   group   by   peopleId,seq     having   count(*)   >   1)   
        
    --4、删除表中多余的重复记录(多个字段),只留有rowid最小的记录   
    delete   from   vitae   a   
    where   (a.peopleId,a.seq)   in     (select   peopleId,seq   from   vitae   group   by   peopleId,seq   having   count(*)   >   1)   
    and   rowid   not   in   (select   min(rowid)   from   vitae   group   by   peopleId,seq   having   count(*)>1)   
        
    --5、查找表中多余的重复记录(多个字段),不包含rowid最小的记录   
    select   *   from   vitae   a   
    where   (a.peopleId,a.seq)   in     (select   peopleId,seq   from   vitae   group   by   peopleId,seq   having   count(*)   >   1)   
    and   rowid   not   in   (select   min(rowid)   from   vitae   group   by   peopleId,seq   having   count(*)>1) 
    
    
    --经典尝试   删除重复值
    
    declare @table table (id int,name nvarchar(10))
    insert into @table select 1,'aa'
            union all  select 1,'aa'
            union all  select 2,'bb'
            union all  select 3,'bb'
            union all  select 4,'cc'
            union all  select 1,'aa'
            union all  select 4,'cc'
    
    delete a
    from (
        select id,name,rn = row_number() over (partition by id,name order by id) from  @table 
    ) a where rn > 1
    
    select * from @table 
    
    id          name
    ----------- ----------
    1           aa
    2           bb
    3           bb
    4           cc
    
    (4 row(s) affected)
    

    常用日期转换参数

    select CONVERT(varchar, getdate(), 120 )
    --结果
    2004-09-12 11:06:08
    select replace(replace(replace(CONVERT(varchar, getdate(), 120 ),'-',''),' ',''),':','')
    --结果
    20040912110608
    select CONVERT(varchar(12) , getdate(), 111 )
    --结果
    2004/09/12
    select CONVERT(varchar(12) , getdate(), 112 )
    --结果
    20040912
    select CONVERT(varchar(12) , getdate(), 102 )
    --结果
    2004.09.12

    行转列

    create table tb(姓名varchar(10) , 课程varchar(10) , 分数int)
    insert into tb values('张三' , '语文' , 74)
    insert into tb values('张三' , '数学' , 83)
    insert into tb values('张三' , '物理' , 93)
    insert into tb values('李四' , '语文' , 74)
    insert into tb values('李四' , '数学' , 84)
    insert into tb values('李四' , '物理' , 94)
    go
    
    select 姓名 as 姓名,
    max(case 课程 when '语文' then 分数 else 0 end) 语文,
    max(case 课程 when '数学' then 分数 else 0 end) 数学,
    max(case 课程 when '物理' then 分数 else 0 end) 物理,
    cast(avg(分数*1.0) as decimal(18,2)) 平均分,
    sum(分数) 总分
    from tb
    group by 姓名
    
    --SQL SERVER 2000 动态SQL。
    declare @sql varchar(8000)
    set @sql = 'select 姓名 '
    select @sql = @sql + ' , max(case 课程 when ''' + 课程 + ''' then 分数 else 0 end) [' + 课程 + ']'
    from (select distinct 课程 from tb) as a
    set @sql = @sql + ' , cast(avg(分数*1.0) as decimal(18,2)) 平均分, sum(分数) 总分 from tb group by 姓名'
    exec(@sql)
    
    --姓名	数学	物理	语文	平均分	总分
    --李四	84	94	74	84.00	252
    --张三	83	93	74	83.33	250

    通过子节点ID得到所有父节点

    ALTER function [dbo].[f_cid](@id int)
    returns @t table(id int,[name] varchar(30),parentid int,lev int)
    as
    begin
         declare @lev int
         set @lev=1
         insert into @t SELECT cid,name,parent_cid,@lev from  TB_ItemCats where cid=@id
         while(@@rowcount>0)
         begin
              set @lev=@lev+1
              insert into @t select a.cid,a.name,a.parent_cid,@lev from TB_ItemCats a,@t b
              where a.cid=b.parentid and b.lev=@lev-1 AND a.cid NOT IN (select b.id from @t)
         end
         return 
    END
    

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  • 原文地址:https://www.cnblogs.com/mmmjiang13/p/1909122.html
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