Oracle分析函数ROW_NUMBER()

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リリース： 2016-06-07 15:50:22

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Oracle分析函数RANK()|ROW_NUMBER()|LAG()使用详解 ROW_NUMBER()函数： row_number()和rownum差不多，功能更强一点（可以在各个分组内从1开时排序），效率更高（？效率貌更差些，实际测验时）。 ROW_NUMBER()的使用方法： ROW_NUMBER() OVER (PARTITION BY C

Oracle分析函数RANK()|ROW_NUMBER()|LAG()使用详解

ROW_NUMBER()函数：

row_number()和rownum差不多，功能更强一点（可以在各个分组内从1开时排序），效率更高（？效率貌似更差些，实际测验时）。

ROW_NUMBER()的使用方法：
    ROW_NUMBER() OVER (PARTITION BY COL1 ORDER BY COL2)
详细说明：
    根据COL1分组
    在分组内部根据 COL2排序
而这个值就表示每组内部排序后的顺序编号（组内连续的唯一的）

ROW_NUMBER（）语法如下：
1、row_number() over(order by column desc)先对列column按照降序，再为每条记录返回一个序列号：
SELECT D.*, ROW_NUMBER() OVER(ORDER BY D.R_OPATE_NUM DESC) AS INX FROM REPORT_DATA D

ROW_NUMBER（）语法如下：

1、row_number() over(order by column desc)先对列column按照降序，再为每条记录返回一个序列号：
SELECT D.*, ROW_NUMBER() OVER(ORDER BY D.R_OPATE_NUM DESC) AS INX FROM REPORT_DATA D

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[sql] view plaincopyprint?

2、row_number() over(partition by column1 order by column2 asc) 先按照column1分组，再对分组后的数据进行以column2升序排列
select personalid,ct_smp_type,row_number() over(partition by personalid order by ct_smp_type asc) rn from neogoodsrule
语法1的具体实例：获取前100名人员的排名信息，如下

2、row_number() over(partition by column1 order by column2 asc) 先按照column1分组，再对分组后的数据进行以column2升序排列
select personalid,ct_smp_type,row_number() over(partition by personalid order by ct_smp_type asc) rn from neogoodsrule 

语法1的具体实例：获取前100名人员的排名信息，如下

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<span>name</span><span>=</span><span>"code"</span><span>></span><span>WITH</span><span> REPORT_DATA </span><span>AS</span><span>  </span>

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(SELECT DW.DWID,DW.DWMC,JY.JYXM,JY.JH,RMPC.R_OPATE_NUM
FROM REPORT_MONTH_PERSON_COUNT RMPC,JWT_JYXX JY,T_DWXX DW
WHERE RMPC.JYID = JY.JYUSERID
AND JY.SSDW = DW.DWID
AND RMPC.R_YEAR = 2013
AND RMPC.R_MONTH = 6
AND JY.SSDW LIKE '4102%'
ORDER BY RMPC.R_OPATE_NUM DESC)
SELECT B.*
FROM (SELECT D.*, ROW_NUMBER() OVER(ORDER BY D.R_OPATE_NUM DESC) AS INX
FROM REPORT_DATA D
) B
WHERE B.INX
ORDER BY B.INX
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<div class="dp-highlighter bg_sql">
<div class="bar"><div class="tools">
<strong>[sql]</strong> <a target="_blank" class="ViewSource" title="view plain" href="http://blog.csdn.net/liqingan880102/article/details/9924257#">view plain</a><a target="_blank" class="CopyToClipboard" title="copy" href="http://blog.csdn.net/liqingan880102/article/details/9924257#">copy</a><a target="_blank" class="PrintSource" title="print" href="http://blog.csdn.net/liqingan880102/article/details/9924257#">print</a><a target="_blank" class="About" title="?" href="http://blog.csdn.net/liqingan880102/article/details/9924257#">?</a>
</div></div>
<ol class="dp-sql">
<li class="alt"><span><span class="keyword">WITH</span><span> REPORT_DATA </span><span class="keyword">AS</span><span>  </span></span></li>
<li>
<span>  (</span><span class="keyword">SELECT</span><span> DW.DWID,DW.DWMC,JY.JYXM,JY.JH,RMPC.R_OPATE_NUM   </span>
</li>
<li class="alt">
<span>  </span><span class="keyword">FROM</span><span> REPORT_MONTH_PERSON_COUNT RMPC,JWT_JYXX JY,T_DWXX DW  </span>
</li>
<li>
<span>  </span><span class="keyword">WHERE</span><span> RMPC.JYID = JY.JYUSERID  </span>
</li>
<li class="alt">
<span>  </span><span class="op">AND</span><span> JY.SSDW = DW.DWID  </span>
</li>
<li>
<span>  </span><span class="op">AND</span><span> RMPC.R_YEAR = 2013  </span>
</li>
<li class="alt">
<span>  </span><span class="op">AND</span><span> RMPC.R_MONTH = 6  </span>
</li>
<li>
<span>  </span><span class="op">AND</span><span> JY.SSDW </span><span class="op">LIKE</span><span> </span><span class="string">'4102%'</span><span>  </span>
</li>
<li class="alt">
<span>  </span><span class="keyword">ORDER</span><span> </span><span class="keyword">BY</span><span> RMPC.R_OPATE_NUM </span><span class="keyword">DESC</span><span>)  </span>
</li>
<li>
<span></span><span class="keyword">SELECT</span><span> B.*  </span>
</li>
<li class="alt">
<span></span><span class="keyword">FROM</span><span> (</span><span class="keyword">SELECT</span><span> D.*, ROW_NUMBER() OVER(</span><span class="keyword">ORDER</span><span> </span><span class="keyword">BY</span><span> D.R_OPATE_NUM </span><span class="keyword">DESC</span><span>) </span><span class="keyword">AS</span><span> INX  </span>
</li>
<li>
<span>       </span><span class="keyword">FROM</span><span> REPORT_DATA D  </span>
</li>
<li class="alt"><span>       ) B  </span></li>
<li>
<span></span><span class="keyword">WHERE</span><span> B.INX </span>
</li>
<li class="alt">
<span></span><span class="keyword">ORDER</span><span> </span><span class="keyword">BY</span><span> B.INX   </span>
</li>
</ol>
</div><pre class="sql" name="code" >WITH REPORT_DATA AS
  (SELECT DW.DWID,DW.DWMC,JY.JYXM,JY.JH,RMPC.R_OPATE_NUM 
  FROM REPORT_MONTH_PERSON_COUNT RMPC,JWT_JYXX JY,T_DWXX DW
  WHERE RMPC.JYID = JY.JYUSERID
  AND JY.SSDW = DW.DWID
  AND RMPC.R_YEAR = 2013
  AND RMPC.R_MONTH = 6
  AND JY.SSDW LIKE &#39;4102%&#39;
  ORDER BY RMPC.R_OPATE_NUM DESC)
SELECT B.*
FROM (SELECT D.*, ROW_NUMBER() OVER(ORDER BY D.R_OPATE_NUM DESC) AS INX
       FROM REPORT_DATA D
       ) B
WHERE B.INX <=100
ORDER BY B.INX

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以下为通过row_number() over(...)删除重复数据的例子，仅供参考：

delete from acc_fundnav
where rowid in (select row1
                   from (select rowid row1,
                                row_number() over(partition by HOST_ID order by rowid) lev
                           from acc_fundnav)
                  where lev > 1)

RANK()：排序的时候跟派名次一样，可以并列2个第一名之后是第3名

LAG：分组排序后，组内后面一条记录减前面一条记录的差，第一条可返回 NULL

BTW: EXPERT ONE ON ONE 上讲的最详细,还有很多相关特性，文档看起来比较费劲

rank()是跳跃排序，有两个第二名时接下来就是第四名（同样是在各个分组内）
dense_rank()l是连续排序，有两个第二名时仍然跟着第三名。
相比之下row_number是没有重复值的
lag（arg1,arg2,arg3):
arg1是从其他行返回的表达式
arg2是希望检索的当前行分区的偏移量。是一个正的偏移量，时一个往回检索以前的行的数目。
arg3是在arg2表示的数目超出了分组的范围时返回的值。