Comments on: Multiple List Left Join in LINQ

By: blake

blake — Tue, 24 Nov 2009 20:15:51 +0000

just what I need, thanks bro

By: bramoin

bramoin — Thu, 03 Sep 2009 16:26:23 +0000

thank you!

By: codingsense

codingsense — Wed, 02 Sep 2009 05:19:52 +0000

Hi bramoin

Use the below query to get all the fields of emp.

var MultipleListJoin = from empdept in
(from emp in ListOfEmployees
join dept in ListOfDepartment
on emp.DeptID equals dept.ID into JoinedEmpDept
from dept in JoinedEmpDept.DefaultIfEmpty()
select new
{
emp,
BranchID = dept != null ? dept.BranchID : 0,
DepartmentName = dept != null ? dept.Name : null
})
join branch in ListOfBranch on
empdept.BranchID equals branch.ID into JoinedwithBranch
from branch in JoinedwithBranch.DefaultIfEmpty()
select new
{
empdept,
DeptName = empdept.DepartmentName,
BranchName = branch != null ? branch.Name : string.Empty
};

Just replacing emp.name with emp will do. later if you need to access any fields of emp then use MultiList.empdept.emp.Name etc. For more clarification please get back.

Thanks,
Naveen Prabhu

By: bramoin

bramoin — Tue, 01 Sep 2009 21:35:00 +0000

Hi,
In your example for left join with multiple lists, it is easy when the class has a one or two members but if the class is large, how do you specify the whole thing rather than writing each one out. I am referring to the line below in the code segment that begins with <<<. (See below)

var MultipleListJoin = from empdept in
(from emp in ListOfEmployees
join dept in ListOfDepartment
on emp.DeptID equals dept.ID into JoinedEmpDept
from dept in JoinedEmpDept.DefaultIfEmpty()
select new
{
EmployeeName = emp.Name, <<< here you just want all the members in the emp, how do you specify that?
BranchID = dept != null ? dept.BranchID : 0,
DepartmentName = dept != null ? dept.Name : null
})
join branch in ListOfBranch on
empdept.BranchID equals branch.ID into JoinedwithBranch
from branch in JoinedwithBranch.DefaultIfEmpty()
select new
{
EmpName = empdept.EmployeeName,
DeptName = empdept.DepartmentName,
BranchName = branch != null ? branch.Name : string.Empty
};

thank you,
bramoin