Question

我遇到了oracle查询的问题。在此查询中，我想显示状态恢复，其中记录采用seq coloumn和extern coloumn的最大值。这是我的疑问：

select x.order_id, z.status_resume,
max(y.seq) as seq2,
max(y.extern_order_status) as extern
from t_order_demand x 
JOIN t_order_log y ON x.order_id=y.order_id
JOIN p_catalog_status z ON z.status_code_sc=y.extern_order_status
and x.order_id like '%1256%'
group by x.order_id, z.status_resume;

这就是结果：
订单ID status_resume seq extern
1256进程2 4
1256注册1 2
1256预先注册0 1

我希望结果只是状态恢复基于seq和extern的最大值。我该怎么做？帮帮我..谢谢。
订单id status_resume seq extern
1256 proccess 2 4

Answer 1

WITH t AS
 (SELECT x.order_id
        ,z.status_resume
        ,MAX(y.seq) AS seq2
        ,MAX(y.extern_order_status) AS extern
  FROM   t_order_demand x
  JOIN   t_order_log y
  ON     x.order_id = y.order_id
  JOIN   p_catalog_status z
  ON     z.status_code_sc = y.extern_order_status
  AND    x.order_id LIKE '%1256%'
  GROUP  BY x.order_id
           ,z.status_resume)
SELECT *
FROM   t
WHERE  (t.seq || t.extern) = (SELECT MAX(tt.seq || tt.extern) FROM t tt);

可能会为你工作。

Answer 2

WITH data AS 
( 
         SELECT   x.order_id, 
                  z.status_resume, 
                  Max(y.seq)                 AS seq2, 
                  Max(y.extern_order_status) AS extern 
         FROM     t_order_demand x 
         join     t_order_log y 
         ON       x.order_id=y.order_id 
         join     p_catalog_status z 
         ON       z.status_code_sc=y.extern_order_status 
         AND      x.order_id LIKE '%1256%' 
         GROUP BY x.order_id, 
                  z.status_resume ) 
SELECT * 
FROM   data 
WHERE  seq || extern = 
(select max(seq || extern) 
FROM   data)
/

要验证的简单测试用例：

SQL> WITH DATA AS(
  2  SELECT 1 col1, 2 col2 FROM dual UNION ALL
  3  SELECT 5, 7 FROM dual
  4  )
  5  SELECT * FROM DATA
  6  where col1||col2 = (select max(col1||col2) from data)
  7  /

      COL1       COL2
---------- ----------
         5          7

SQL>

Answer 3

您可以使用分析函数RANK：

select order_id, status_resume, seq2, extern 
from (
    select x.order_id, z.status_resume,
           max(y.seq) as seq2,
           max(y.extern_order_status) as extern,
           rank() over(partition by x.order_id, z.status_resume order by max(y.seq) desc, max(y.extern_order_status) desc) rnk
    from t_order_demand x 
    JOIN t_order_log y ON x.order_id=y.order_id
    JOIN p_catalog_status z ON z.status_code_sc=y.extern_order_status
    and x.order_id like '%1256%'
    group by x.order_id, z.status_resume
) where rnk = 1;

但目前尚不清楚最多两个字段是什么意思。总和？上面的查询使用max seq检索行，如果多行具有相同的seq，则只检索max extern_order_status行。

获取基于最大值oracle多个表的记录

3 个答案: