zoukankan      html  css  js  c++  java
  • 整理Oracle分拆合并表

    Oracle分拆合并表

    /****************************************************************************************
    Oracle分拆合并表
    
    整理人:中國風(Roy)
    日期:2011.11.02
    *****************************************************************************************/
    
    /**--合并
    
    --模拟数据
    Col1	Col2
    1	a
    1	b
    1	c
    2	d
    2	e
    3	f
    **/
    
    /**--生成结果
    
    COL1 	COL2
    1 	a,b,c
    2 	d,e
    3 	f 
    **/
    
    
    /**oracle10g以上版本字符串函数wmsys.wm_concat**/
    
    /**方法1**/
    with Tab
    as
    (
    select 1 as Col1,'a'  as Col2 from dual union all
    select 1,'b' from dual  union all
    select 1,'c' from dual union all
    select 2,'d' from dual union all
    select 2,'e' from dual union all
    select 3,'f' from dual 
    )
    select
    	Col1,wmsys.wm_concat(Col2 ) as Col2
    from tab  group by Col1
    
    
    /**oracle9i可以用connect by**/
    
    /**方法2**/
    with Tab
    as
    (
    select 1 as Col1,'a'  as Col2 from dual union all
    select 1,'b' from dual  union all
    select 1,'c' from dual union all
    select 2,'d' from dual union all
    select 2,'e' from dual union all
    select 3,'f' from dual 
    )
    select 
    	Col1,substr(max(sys_connect_by_path(Col2,',')),2) Col2
    from 
    	(select a.*,row_number()over(partition by Col1 order by Col1) rn from Tab a )
    group by Col1 start with rn=1
    connect by rn-1=prior rn and Col1=prior Col1
    order by Col1;
    
    /**--分拆
    
    --模拟数据
    Col1	Col2
    1	a,b,c
    2	d,e
    3	f
    **/
    
    /**--生成结果
    
    COL1 	COL2
    1 	a
    1 	b
    1 	c
    2 	d
    2 	e
    3 	f 
    **/
    /**方法1**/
    with Tab
    as
    (select 1 as Col1,N'a,b,c' as Col2  from dual union all
    select 2,N'd,e' from dual union all
    select 3,N'f'   from dual )
    SELECT 
          Col1,substr(Col2,lev,instr(Col2||',',',',lev)-lev) as Col2
    from Tab 
    	,(SELECT LEVEL lev FROM DUAL CONNECT BY LEVEL<=100)
    WHERE 
    	substr(','||Col2,lev,1)=',' /** 条件可换为 instr(','||Col2,',',lev)=lev**/
    order by Col1
    
    /**方法2
    REGEXP_SUBSTR(srcstr, pattern, position, occurrence, modifier)  
    __srcstr        :检索字符串
    __pattern      :匹配模式
    __position     :搜索srcstr的起始位置(默认为1)
    __occurrence:搜索第几次出现匹配模式的字符串(默认为1)
    __modifier     :检索模式('i'不区分大小写进行检索;'c'区分大小写进行检索。默认为'c'。)  
    **/
    
    with Tab
    as
    (select 1 as Col1,N'a,b,c' as Col2  from dual union all
    select 2,N'd,e' from dual union all
    select 3,N'f'   from dual )
    SELECT 
    	Col1,REGEXP_SUBSTR(Col2,'[^,]+',1,lev)
    FROM Tab,
    	(SELECT LEVEL lev FROM dual CONNECT BY LEVEL <= 100) b
    WHERE (LENGTH(Col2)-LENGTH(REPLACE(Col2,',','')))+1 >=lev
    ORDER BY Col1,lev



    SQL Server 拆分合并表方法

    点击打开链接

  • 相关阅读:
    [YNOI2017][bzoj4811][luogu3613] 由乃的OJ/睡觉困难综合症 [压位+树链剖分+线段树]
    [bzoj3270] 博物馆 [期望+高斯消元]
    [bzoj4372] 烁烁的游戏 [动态点分治+线段树+容斥原理]
    [Codeforces438E][bzoj3625] 小朋友和二叉树 [多项式求逆+多项式开根]
    [bzoj3813] 奇数国 [线段树+欧拉函数]
    [BZOJ4205][FJ2015集训] 卡牌配对 [建图+最大流]
    Git常见问题解决办法
    电脑常用快捷键
    egret.Shape渲染集合图形
    TypeScript语法学习--变量的声明
  • 原文地址:https://www.cnblogs.com/Roy_88/p/5463066.html
Copyright © 2011-2022 走看看