subquery using IN clause

Question

----------
User
----------
user_ID(pk)
UserEmail

----------
Employer1
----------
Emp1ID(pk)
Emp1NO

----------
Employer2
----------
Emp2ID(pk)
Emp2NO

----------
Pr         


        

Answer 1

You can only return one column from your subquery. If you just want both the employee ID and manager ID consider a union query as your subquery:

    emp.Emp2NO IN
(select ProjEmpID from project
 union
 select ProjEmpMGRID from project)

or rewriting to use two IN queries with separate subqueries for each.