Convert SQL to LINQ to Entities WHERE IN clause

问题

How can I convert this sql statetment to LINQ to Entities?

SQL Statement:

Select * from Departments where DepartmentID  in (Select DepartmentID from Employees where FirstName like '%FirstName%' or LastName like '%LastName%')

---

All I have is WHERE =(equals) , I can't do the WHERE IN clause

LINQ to Entities:

from t in db.Departments
where
  t.DepartmentID == -->Should be IN not EQUALS
    ((from t0 in db.Employees
    where
      t0.FirstName.Contains("FirstName") ||
      t0.LastName.Contains("LastName")
    select new {
      t0.DepartmentID
    }).FirstOrDefault().DepartmentID)
select t

回答1:

(from d in db.Departments
 join e in db.Employees
     on d.DepartmentID equals e.DepartmentID
 where e.FirstName.Contains("FirstName") ||
       e.LastName.Contains("LastName")
 select t).Distinct()

回答2:

u could use this

var x = 
    (from t0 in db.Employees
    where
      t0.FirstName.Contains("FirstName") ||
      t0.LastName.Contains("LastName")
    select new {
      t0.DepartmentID
    }).FirstOrDefault().DepartmentID;

from t in db.Departments
where
  t.DepartmentID.contains(x.DepartmentID)
select t

来源：https://stackoverflow.com/questions/16555471/convert-sql-to-linq-to-entities-where-in-clause