如何使用内部连接更新行

Posted 2023-05-09

【中文标题】如何使用内部连接更新行

【英文标题】：How update row with inner joins

【发布时间】：2020-09-03 09:46:56

【问题描述】：

我有这个选择语句，我在其中找到了两行，我想更新一个特定的列：

select * from murex.STPDLV_ENTRY_TABLE a 
inner join (select DLV_FLOW_XX, max(TS_TIME_LONG) AS MaxDateTime from murex.STPDLV_ENTRY_TABLE group by DLV_FLOW_XX) b 
on a.DLV_FLOW_XX = b.DLV_FLOW_XX
and a.TS_TIME_LONG=b.MaxDateTime
and a.DLV_FLOW_XX in (3741539,4044126,3741551)
and a.STP_UDF9 !='Posted';

我试过了：

update STPDLV_ENTRY_TABLE a
set a.STP_UDF9 = 'Posted'
where
inner join (select DLV_FLOW_XX, max(TS_TIME_LONG) AS MaxDateTime from murex.STPDLV_ENTRY_TABLE group by DLV_FLOW_XX) b 
on a.DLV_FLOW_XX = b.DLV_FLOW_XX
and a.TS_TIME_LONG=b.MaxDateTime
and a.DLV_FLOW_XX in (3741539,4044126,3741551);

如何正确构造更新查询？

解决方案：

update (select * 
        from STPDLV_ENTRY_TABLE a 
        inner join (select DLV_FLOW_XX
                           , max(TS_TIME_LONG) AS MaxDateTime 
                    from STPDLV_ENTRY_TABLE 
                    group by DLV_FLOW_XX) b 
        on a.DLV_FLOW_XX = b.DLV_FLOW_XX
        and a.TS_TIME_LONG = b.MaxDateTime
        and a.DLV_FLOW_XX in (3741539,4044126,3741551)
        and a.STP_UDF9 !='Posted') test
set test.STP_UDF9 = 'Posted';

【问题讨论】：

你想更新什么？

抱歉我已经编辑了脚本

***.com/questions/tagged/oracle+join+sql-update

【参考方案1】：

只需将您的查询作为表格：

update (select * 
        from STPDLV_ENTRY_TABLE a 
        inner join (select DLV_FLOW_XX
                           , max(TS_TIME_LONG) AS MaxDateTime 
                    from STPDLV_ENTRY_TABLE 
                    group by DLV_FLOW_XX) b 
        on a.DLV_FLOW_XX = b.DLV_FLOW_XX
        and a.TS_TIME_LONG = b.MaxDateTime
        and a.DLV_FLOW_XX in (3741539,4044126,3741551)
        and a.STP_UDF9 !='Posted') test
set test.STP_UDF9 = 'Posted';

这是一个演示：

DEMO

【参考方案2】：

对我来说，merge 看起来是一个更好/更简单的选择。

MERGE INTO stpdlv_entry_table a
     USING (  SELECT dlv_flow_xx, MAX (ts_time_long) AS maxdatetime
                FROM murex.stpdlv_entry_table
            GROUP BY dlv_flow_xx) b
        ON (    a.dlv_flow_xx = b.dlv_flow_xx
            AND a.ts_time_long = b.maxdatetime)
WHEN MATCHED
THEN
   UPDATE SET a.stp_udf9 = 'Posted'
           WHERE a.dlv_flow_xx IN (3741539, 4044126, 3741551);