Question

当我执行此查询时，收到以下错误消息：

＆＃34; Ora-01427单行子查询返回多行＆＃34;

UPDATE event_registrations xta
SET (event_start_date,
     event_end_date,
     planned_hours,
     user_status,
     last_updated_date,
     last_updated_by,
     last_update_sec) =
     (SELECT xcat.event_start_date,
          CASE
              WHEN xt.event_status = g_closed_s THEN xta.event_end_date
              WHEN xt.event_status = g_open_s THEN xcat.event_end_date
          END,
          xcat.planned_hours,
          CASE
              WHEN xt.event_status = g_closed_s THEN g_status_done
              WHEN xt.event_status = g_open_s THEN g_status_inprogress
          END,
          SYSDATE,
          p_login_user,
          to_number(TO_CHAR(SYSDATE, g_time_format))

   FROM     event_registrations_temp xcat
   LEFT     OUTER JOIN EVENTS xt ON xt.ext_system_id = xcat.alm_id
   WHERE    xcat.action = g_action_modification
   AND      xcat.error_flag = g_err_flag_not_processed
   AND      xcat.event_registration_id = xta.ext_event_registration_id)
   WHERE    xta.ext_event_registration_id IN
            (SELECT event_registration_id
             FROM   event_registrations_temp
             WHERE  action = g_action_modification
             AND    error_flag = g_err_flag_not_processed);

我尝试使用IN条件修复它，但它确实无法正常工作。任何人都可以帮我这个。

Answer 1

要返回更新值的子查询返回多个记录。所以要么

event_registrations_temp每个action + error_flag + event_registration_id

或

每个events有多个ext_system_id。

检查event_registrations_temp：

select action, error_flag, event_registration_id
from event_registrations_temp
group by action, error_flag, event_registration_id
having count(*) > 1;

检查events：

select ext_system_id
from events
group by ext_system_id
having count(*) > 1;

一旦您知道这两个问题中的哪一个，请记下如何决定您想要更新的一条记录，并将此条件添加到子查询中。这可以是WHERE子句中的其他条件或某些聚合。

Answer 2

这被称为相关更新＆＃39;和IN不是解决方案。但是在更新中使用它之前，您需要先检查select语句。

UPDATE event_registrations xta
SET (event_start_date,
     event_end_date,
     planned_hours,
     user_status,
     last_updated_date,
     last_updated_by,
     last_update_sec) =
     (SELECT xcat.event_start_date,
          CASE
              WHEN xt.event_status = g_closed_s THEN xta.event_end_date
              WHEN xt.event_status = g_open_s THEN xcat.event_end_date
          END,
          xcat.planned_hours,
          CASE
              WHEN xt.event_status = g_closed_s THEN g_status_done
              WHEN xt.event_status = g_open_s THEN g_status_inprogress
          END,
          SYSDATE,
          p_login_user,
          to_number(TO_CHAR(SYSDATE, g_time_format))

   FROM     event_registrations_temp xcat
   LEFT     OUTER JOIN EVENTS xt ON xt.ext_system_id = xcat.alm_id
   WHERE    xcat.action = g_action_modification
   AND      xcat.error_flag = g_err_flag_not_processed
   AND      xcat.event_registration_id = xta.ext_event_registration_id)
   WHERE    xta.ext_event_registration_id =xcat.event_registration_id)
  where  exists (SELECT 1
      FROM event_registrations_temp xcat
     WHERE xcat.event_registration_id = xta.ext_event_registration_id)

Answer 3

这是一个简单的问题。检查event_registrations_temp是否可以包含每个操作多个记录或error_flag或event_registration_id

select action, error_flag, event_registration_id
from event_registrations_temp
group by action, error_flag, event_registration_id
having count(*) > 1;

如何修复单行子查询在下面的查询中返回多行？

3 个答案: