Question

我有2个表：一个包含核心数据的主要APPLICATION表，以及一个反映APPLICATION表中核心数据状态变化的STATUSTRACKING表。

APPLICATION表和STATUSTRACKING表之间存在1：N的关系。示例如下：

-- APPLICATION
SELECT A.ID, A.DECISIONON, A.APPLICATIONSTATUS_ID AS CURRENTSTATUS
FROM APPLICATION A
WHERE A.ID=1099;

Results:
ID      DECISIONON  CURRENTSTATUS
1099    5/05/2009   5

-- STATUS TRACKING
SELECT ST.ID, ST.APPLICATION_ID AS APP_ID, ST.APPLICATIONSTATUS_ID AS STATUS, ST.CREATEDATE 
FROM STATUSTRACKING ST
WHERE ST.APPLICATION_ID=1099
ORDER BY ST.CREATEDATE DESC;

Results:
ID      APP_ID  STATUS  CREATEDATE
44466   1099    5       5/05/2009
44458   1099    7       5/05/2009
10826   1099    8       21/07/2008
9770    1099    7       9/07/2008
4410    1099    3       9/05/2008
3814    1099    2       2/05/2008
3803    1099    1       2/05/2008

问题：我需要选择具有最近日期的STATUSTRACKING记录以获取特定状态。这是我的尝试：

SELECT A.ID AS APP_ID, A.APPLICATIONSTATUS_ID AS CURR_ST, Z.ID AS ST_ID, Z.CREATEDATE, Z.APPLICATIONSTATUS_ID AS OLD_ST
FROM APPLICATION A, STATUSTRACKING Z
WHERE A.APPLICATIONSTATUS_ID in (5,6)
    AND A.ID IN (337,1099,1404,9441)
    AND Z.APPLICATIONSTATUS_ID = 7
    AND Z.APPLICATION_ID=A.ID
ORDER BY A.ID ASC, Z.CREATEDATE DESC;

Results:
APP_ID  CURR_ST ST_ID       CREATEDATE  OLD_ST
337     6       13978       17/08/2008  7
1099    5       44458       5/05/2009   7
1099    5       9770        9/07/2008   7
1404    6       15550       28/08/2008  7
9441    5       49271       3/06/2009   7
9441    5       46058       13/05/2009  7

问题是重复的行。我必须只显示MOST RECENT CreateDate的行。在App_ID 1099的情况下，它将是此记录：

1099    5       44458       5/05/2009   7

我显然不想排除那些没有重复的行。

我认为我在这条声明的正确轨道上给出了我正在寻找的行：

SELECT A.ID, A.APPLICATION_ID, A.APPLICATIONSTATUS_ID, A.CREATEDATE
FROM    (SELECT * 
            FROM STATUSTRACKING 
            WHERE APPLICATIONSTATUS_ID=7 
                AND APPLICATION_ID=1099 
            ORDER BY CREATEDATE DESC) A
WHERE ROWNUM = 1;

...但我似乎无法使用我的主要选择声明。

我想要的结果集应如下所示：

APP_ID  CURR_ST ST_ID       CREATEDATE  OLD_ST
337     6       13978       17/08/2008  7
1099    5       44458       5/05/2009   7
1404    6       15550       28/08/2008  7
9441    5       49271       3/06/2009   7
etc. ...

我不是Oracle / SQL专家，所以任何帮助都会受到赞赏。

Answer 1

最简单的方法可能是使用分析函数。像

这样的东西

SELECT *
  FROM (
    SELECT A.ID AS APP_ID, 
           A.APPLICATIONSTATUS_ID AS CURR_ST, 
           Z.ID AS ST_ID, 
           Z.CREATEDATE, 
           Z.APPLICATIONSTATUS_ID AS OLD_ST,
           rank() over (partition by a.id order by z.createDate desc) rnk
      FROM APPLICATION A, 
           STATUSTRACKING Z
     WHERE A.APPLICATIONSTATUS_ID in (5,6)
       AND A.ID IN (337,1099,1404,9441)
       AND Z.APPLICATIONSTATUS_ID = 7
       AND Z.APPLICATION_ID=A.ID
    )
 WHERE rnk = 1

如果可能存在关联，您可能需要使用ROW_NUMBER或DENSE_RANK分析函数而不是RANK。

Answer 2

如果我理解正确，您需要该应用的最新状态，对吧？问题：您的创建日期也有时间（小时，分钟和秒）？也许这个查询可以帮助你：

select a.* , st.*
  from application a
     , statustracking st
 where a.id = st.app_id
   and st.createdate = ( select max(st1.createdate)
                           from statustracing st1
                          where st1.app_id = a.id
                            and st1.application_statusid = st.application_statusid  )
   -- filters goes there
   and a.id in (....)
   and st.application_statusid in (...)

如何基于多个表从Oracle结果集中删除重复项

2 个答案: