我在表中有一个名为“client_name”的列......我需要从我的联接查询的最后一行中选择列值

Question

我有一个列名为 policy_refer、客户名称和 issue_date 的表

policy_refer    Client_Name   issue_date(entry_date)
0001             Ajaz         01-Jan-2019
0001             Ajaz         05-Jan-2019
0001             Anita        10-Jan-2019

我想在我的选择/加入查询中选择最后一次更新/插入 client_name where policy_refer = 0001 ....

select policy_master.CLIENT_NAME
      ,POLICY_INSURER_DETAIL.INSURER_NAME
      ,POLICY_INSURER_DETAIL.INSURER_BRANCH
      ,POLICY_INSURER_DETAIL.policy_number
      ,policy_master.policy_refer
      ,policy_master.POLICY_CLASS
      ,policy_master.POLICY_PRODUCT
      ,policy_master.P_ISSUE_DATE
      ,policy_master.EXPIRY_DATE
      ,sum(policy_master.TOTAL_SUMINSURED)
      ,sum(policy_master.GROSS)
      ,sum(policy_master.PERMIUM)
from POLICY_MASTER,POLICY_INSURER_DETAIL
where policy_master.policy_refer = POLICY_INSURER_DETAIL.POLICY_REFER
and POLICY_MASTER.POL_ID = POLICY_INSURER_DETAIL.POL_ID
and POLICY_MASTER.EXPIRY_DATE ='19-AUG-20'
and POLICY_MASTER.DOC_STATUS ='Posted'
group by POLICY_MASTER.policy_refer
        ,POLICY_INSURER_DETAIL.INSURER_NAME
        ,POLICY_INSURER_DETAIL.INSURER_BRANCH
        ,POLICY_INSURER_DETAIL.policy_number
        ,policy_master.policy_refer
        ,policy_master.EXPIRY_DATE
        ,policy_master.CLIENT_NAME
        ,policy_master.POLICY_CLASS
        ,policy_master.POLICY_PRODUCT
        ,policy_master.P_ISSUE_DATE;

Answer 1

一个选项是找出哪个是第一个（使用分析函数），然后获取该行。例如：

select column_list_goes_here
from (
        --> this is your current query, with the ROW_NUMBER addition
        select all your columns here,
        --
        row_number() over (partition by policy_refer order by issue_date desc) rn
        --
      from your_tables
      where ...
      group by ...
      --> end of your current query
      )
where rn = 1      

Answer 2

您正在谈论的表格似乎是 POLICY_MASTER 表格，并且您想要每个策略的最新行（ISSUE_DATE）。

然后你想过滤这样的东西：

select pm.CLIENT_NAME
      ,POLICY_INSURER_DETAIL.INSURER_NAME
      ,POLICY_INSURER_DETAIL.INSURER_BRANCH
      ,POLICY_INSURER_DETAIL.policy_number
      ,pm.policy_refer
      ,pm.POLICY_CLASS
      ,pm.POLICY_PRODUCT
      ,pm.P_ISSUE_DATE
      ,pm.EXPIRY_DATE
      ,sum(pm.TOTAL_SUMINSURED)
      ,sum(pm.GROSS)
      ,sum(pm.PERMIUM)
from   (
         SELECT *
         FROM   (
           SELECT POL_ID,
                  CLIENT_NAME,
                  policy_refer,
                  POLICY_CLASS,
                  POLICY_PRODUCT,
                  P_ISSUE_DATE,
                  EXPIRY_DATE,
                  TOTAL_SUMINSURED,
                  GROSS,
                  PERMIUM,
                  ROW_NUMBER() OVER ( PARTITION BY policy_refer /*, pol_id */
                                      ORDER BY ISSUE_DATE DESC ) AS rn
           FROM   POLICY_MASTER
           WHERE  EXPIRY_DATE = DATE '2020-08-19'
           AND    DOC_STATUS  ='Posted'
         )
         WHERE rn = 1
       ) pm
       INNER JOIN POLICY_INSURER_DETAIL pid
       ON (     pm.policy_refer = pid.POLICY_REFER
            AND pm.POL_ID       = pid.POL_ID )
GROUP BY pm.policy_refer
        ,pid.INSURER_NAME
        ,pid.INSURER_BRANCH
        ,pid.policy_number
        ,pm.policy_refer
        ,pm.EXPIRY_DATE
        ,pm.CLIENT_NAME
        ,pm.POLICY_CLASS
        ,pm.POLICY_PRODUCT
        ,pm.P_ISSUE_DATE;

Answer 3

我猜你需要从发布日期降序排序后的第一行 -

select policy_master.CLIENT_NAME
      ,POLICY_INSURER_DETAIL.INSURER_NAME
      ,POLICY_INSURER_DETAIL.INSURER_BRANCH
      ,POLICY_INSURER_DETAIL.policy_number
      ,policy_master.policy_refer
      ,policy_master.POLICY_CLASS
      ,policy_master.POLICY_PRODUCT
      ,policy_master.P_ISSUE_DATE
      ,policy_master.EXPIRY_DATE
      ,sum(policy_master.TOTAL_SUMINSURED)
      ,sum(policy_master.GROSS)
      ,sum(policy_master.PERMIUM)
from POLICY_MASTER,POLICY_INSURER_DETAIL
where policy_master.policy_refer = POLICY_INSURER_DETAIL.POLICY_REFER
and POLICY_MASTER.POL_ID = POLICY_INSURER_DETAIL.POL_ID
and POLICY_MASTER.EXPIRY_DATE ='19-AUG-20'
and POLICY_MASTER.DOC_STATUS ='Posted'
and rownum = 1
group by POLICY_MASTER.policy_refer
        ,POLICY_INSURER_DETAIL.INSURER_NAME
        ,POLICY_INSURER_DETAIL.INSURER_BRANCH
        ,POLICY_INSURER_DETAIL.policy_number
        ,policy_master.policy_refer
        ,policy_master.EXPIRY_DATE
        ,policy_master.CLIENT_NAME
        ,policy_master.POLICY_CLASS
        ,policy_master.POLICY_PRODUCT
        ,policy_master.P_ISSUE_DATE
ORDER BY P_ISSUE_DATE DESC;