Oracle Partition By 的使用

需求:以FSENDCCNAME分组找出FRECAMOUNT最大的一行信息；

解决方案 1：

SELECT T0.FSENDCCNAME,T0.FRECCCNAME
  FROM TMP0CE8366758A811E781D70050568 T0
       INNER JOIN
       (  SELECT FSENDCCNAME, MAX (FRECAMOUNT) FRECAMOUNT
            FROM TMP0CE8366758A811E781D70050568
           WHERE FGROUPING = 0
        GROUP BY FSENDCCNAME
        ORDER BY FSENDCCNAME, FRECAMOUNT DESC) T1
          ON     T1.FSENDCCNAME = T0.FSENDCCNAME
             AND T1.FRECAMOUNT = T0.FRECAMOUNT
 WHERE T0.FGROUPING = 0;

解决方案 2：

--按顺序排序
SELECT row_number () OVER (PARTITION BY fsendccname ORDER BY frecamount DESC)
                  rn,
               a.*
          FROM TMP0CE8366758A811E781D70050568 a
         WHERE fgrouping = 0 and FGROUPLEVEL<> 1

显示结果如下：

解决方案 3：

--跳跃排序

SELECT RANK () OVER (PARTITION BY FSENDCCNAME ORDER BY FRECAMOUNT DESC)
                  RN,
               A.*
          FROM TMP0CE8366758A811E781D70050568 A
         WHERE FGROUPING = 0 AND FGROUPLEVEL<> 1

显示结果如下：

解决方案 4：

--连续排序
SELECT DENSE_RANK () OVER (PARTITION BY FSENDCCNAME ORDER BY FRECAMOUNT DESC)
                  RN,
               A.*
          FROM TMP0CE8366758A811E781D70050568 A
         WHERE FGROUPING = 0 AND FGROUPLEVEL<> 1

显示结果如下：