Question

内部查询如下，可以独立工作

select graduate.univid
from graduate, projectmanager, university
where graduate.empid = projectmanager.mgrid and rownum = 1
group by graduate.univid
order by count(graduate.univid) desc;

但是当作为子查询使用时，ORACLE sqlplus继续给出＆＃34;缺少右括号＆＃34;错误

select university.univname
from university
where exists 
(
select graduate.univid
from graduate, projectmanager, university
where graduate.empid = projectmanager.mgrid and rownum = 1
group by graduate.univid
order by count(graduate.univid)
);

我已经检查过stackoverflow上的类似问题，但并没有真正帮助

Answer 1

你使用存在，所以你必须给出大学和子查询的条件。你错过了，你得到错误，我猜错了正确的查询：

select t1.univname
from university t1
where exists 
(  select 1 from (
   select graduate.univid
   from graduate, projectmanager, university
   where graduate.empid = projectmanager.mgrid and rownum = 1
   group by graduate.univid
   order by count(graduate.univid)) t2 where t2.univid = t1.univid
);

Answer 2

假设您的其余逻辑正确，则问题是order by子句。你应该不在子查询中使用它。试试这个

select university.univname
from university
where exists 
(
select graduate.univid
from graduate, projectmanager, university
where graduate.empid = projectmanager.mgrid and rownum = 1
group by graduate.univid
);

你可以自己尝试一下。

此查询将返回1

select 1 from dual
where exists
(select 2 as id from dual)

但这会失败并给你ORA-00907: missing right parenthesis

select 1 from dual
where exists
(select 2 as id from dual order by id )

oracle，添加子查询时缺少右括号

2 个答案: