oracle - 更新语句中的“单行子查询返回多行”

Question

几天来，我一直在努力弄清楚如何使我的update陈述发挥作用。该select语句似乎按预期工作，但是当我尝试更新列值时出现ORA-01427 single-row subquery returns more than one row错误。

这是代码：

UPDATE tbl_metrics
SET act_end_time = (WITH base
AS (SELECT caseid, entry_timestamp
       FROM activity
      WHERE act_id IN (100, 700, 300)
      )  
SELECT t1.entry_timestamp
FROM base t1, tbl_metrics t2
WHERE t1.caseid = t2.caseid
AND t2.act_start_time < (SELECT MIN(t1.entry_timestamp) FROM base t1 WHERE t1.caseid = t2.caseid))

这个想法是使用表中的最小值tbl_metrics.act_end_time更新列，其中and是100、700 或 300。entry_timestampactivityactivity.caseid=tbl_metrics.caseidactivity.entry_timestamp>tbl_metrics.act_start_timeactivity.act_id

Answer 1

我认为应该是这样的：

UPDATE tbl_metrics t2
SET act_end_time = 
    (SELECT MIN(t1.entry_timestamp) 
    FROM activity t1 
    WHERE act_id IN (100, 700, 300)
        AND t1.entry_timestamp > t2.act_start_time
        AND t1.caseid = t2.caseid)