Question

I had tried to join two table conditionally but it is giving me syntax error. I tried to find solution in the net but i cannot find how to do conditional join with condition. The only other alternative is to get the value first from one table and make a query again.

I just want to confirm if there is any other way to do conditional join with linq.

Here is my code, I am trying to find all position that is equal or lower than me. Basically I want to get my peers and subordinates.

from e in entity.M_Employee
join p in entity.M_Position on e.PostionId >= p.PositionId
select p;

Answer 1

You can’t do that with a LINQ joins – LINQ only supports equijoins. However, you can do this:

var query = from e in entity.M_Employee
            from p in entity.M_Position
            where e.PostionId >= p.PositionId
            select p;

Or a slightly alternative but equivalent approach:

var query = entity.M_Employee
                  .SelectMany(e => entity.M_Position
                                      .Where(p => e.PostionId >= p.PositionId));