Sql 返回多行的子查询

我在下面的查询中得到一个错误。。有人能帮忙解决这个问题吗

select c.CHANGE_NUMBER, 
(select le.ENTRYVALUE from listentry  le
where le.ENTRYID = c.CATEGORY)as CATEGORY ,
(
            SELECT  last_name || ',' || first_name || '(' || loginid || ')'
            FROM agileuser
            WHERE id = c.ORIGINATOR
        ) initiator,(
            SELECT  last_name || ',' || first_name || '(' || loginid || ')'
            FROM agileuser
            WHERE id = c.owner
        ) coordinator, w.state,

(SELECT description
            FROM nodetable
            WHERE id = w.state
        ) workflow_status , TO_CHAR(w.LOCAL_DATE,'DD-MON-YY HH24:MI:SS')local_date,
      (select  
        (trunc(to_date(B.local_date, 'DD-MON-YY HH24:MI:SS') - to_date(w.local_date, 'DD-MON-YY HH24:MI:SS')))as timediff
        FROM WORKFLOW_PROCESS w INNER JOIN WORKFLOW_PROCESS B ON B.order_by = (w.order_by + 1) 
        where w.change_id=B.Change_id and w.change_id=9946301 )--ORDER BY w.order_by ASC 

       from change c, WORKFLOW_PROCESS w 
        where w.change_id = c.id-- order by w.ORDER_BY)
       and c.CHANGE_NUMBER='NPI001084' 
      order by w.ORDER_BY,local_date ASC 

trunc（）查询提供多条记录

 select  
     (trunc(to_date(B.local_date, 'DD-MON-YY HH24:MI:SS') - to_date(w.local_date, 'DD-MON-YY HH24:MI:SS')))as timediff
      FROM WORKFLOW_PROCESS w INNER JOIN WORKFLOW_PROCESS B ON B.order_by = (w.order_by + 1) 
      where w.change_id=B.Change_id and w.change_id=9946301 ORDER BY w.order_by ASC 

---

因此无法执行此主查询。

真是一团糟！您确实应该考虑使用SQL格式化程序，或者如果由于某种原因不能使用，请尝试手动编写代码格式。这是不可读的

无论如何：尽管子查询看起来是解决问题的好方法，但通常-避免它们。其中大部分都可以重写，以便正确地联接相关的表

如果选择在

SELECT

语句中使用它们，则必须确保它们每个都返回一个值

这将返回两行或更多行：

SELECT (TRUNC (
             TO_DATE (b.local_date, 'DD-MON-YY HH24:MI:SS')
           - TO_DATE (w.local_date, 'DD-MON-YY HH24:MI:SS')))
          AS timediff
  FROM workflow_process w
       INNER JOIN workflow_process b ON b.order_by = (w.order_by + 1)
 WHERE     w.change_id = b.change_id
       AND w.change_id = 9946301

如何修复它？我不知道，我没有你的桌子，也不知道你想要什么。简单的选择可能是：

select distinct timediff ...

或

或

---

或者其他一些选项，但是-同样，这取决于我们不知道的东西。

完全未经测试，可能有一些拼写错误，也可能是应该保留的连接，可能是不正确的oracle语法，但是

select c.CHANGE_NUMBER, 
    le.ENTRYVALUE as CATEGORY
    orig.last_name || ',' || orig.first_name || '(' || orig.loginid || ')' as initiator,
    own.last_name || ',' || own.first_name || '(' || own.loginid || ')' as coordinator,
    w.state,
    n.description as workflow_status,
    TO_CHAR(w.LOCAL_DATE,'DD-MON-YY HH24:MI:SS')local_date,
    trunc(to_date(B.local_date, 'DD-MON-YY HH24:MI:SS') - to_date(w.local_date, 'DD-MON-YY HH24:MI:SS')) as timediff
from change c
join WORKFLOW_PROCESS w on w.change_id = c.id
join listentry le on le.ENTRYID = c.CATEGORY
join agileuser as orig on orig.id = c.ORIGINATOR
join agileuser as own on own.id = c.owner
join nodetable as n on n.id = w.state
JOIN WORKFLOW_PROCESS B ON B.order_by = (w.order_by + 1) 
where c.CHANGE_NUMBER='NPI001084' 
order by w.ORDER_BY,local_date ASC 

---

非常感谢你们两位。我对它完全陌生，并试图弄明白。在添加子查询之前，上面的查询为我提供了预期的结果。这个查询多次打印相同的行，我不能在任何列中使用distinct。有什么建议吗？同一行多次是您问题的根源。只需优化查询以仅选择一个，或者使用row_number（）函数选择任何组中的第一个。或者，如果它们在所有这些列中确实是重复的，则使用SELECT DISTINCT。

select ...
where rownum = 1

select c.CHANGE_NUMBER, 
    le.ENTRYVALUE as CATEGORY
    orig.last_name || ',' || orig.first_name || '(' || orig.loginid || ')' as initiator,
    own.last_name || ',' || own.first_name || '(' || own.loginid || ')' as coordinator,
    w.state,
    n.description as workflow_status,
    TO_CHAR(w.LOCAL_DATE,'DD-MON-YY HH24:MI:SS')local_date,
    trunc(to_date(B.local_date, 'DD-MON-YY HH24:MI:SS') - to_date(w.local_date, 'DD-MON-YY HH24:MI:SS')) as timediff
from change c
join WORKFLOW_PROCESS w on w.change_id = c.id
join listentry le on le.ENTRYID = c.CATEGORY
join agileuser as orig on orig.id = c.ORIGINATOR
join agileuser as own on own.id = c.owner
join nodetable as n on n.id = w.state
JOIN WORKFLOW_PROCESS B ON B.order_by = (w.order_by + 1) 
where c.CHANGE_NUMBER='NPI001084' 
order by w.ORDER_BY,local_date ASC