———-
User
———-
user_ID(pk)
UserEmail
———-
Project_Account
———-
actno
actname
projno
projname
ProjEmpID
ProjEmpMGRID
其中ProjEmpID,ProjEmpMGRID是user_id,ProjEmpMGRID可以为null.
我需要查找useremail并显示表project_account.我需要使用具有重复值的actNo进行查询.
我的查询是这样的：
select projno,projname,actno,actname,
(select u.user_email as project_manager from project_account c left outer join users u
on u.user_id = c.ProjEmpID where actno=’some no’)as project_manager,
(select u.user_email as program_manager from project_account c left outer join users u
on u.user_id = c.ProjEmpMGRID where actno=’someno’) as program_manager
from project_account where actno=’someno’
我在Oracle中收到的错误消息：
ora-01427 single row subquery returns
more than one row
当我的子查询返回多个电子邮件ID时,我收到此错误.正如我所说,行为不是不唯一的.我能理解错误,但我无法弄清楚解决方案.我在子查询中执行左外连接,因为prog manager id中可能有空值.
任何帮助,将不胜感激.