Question

I want to convert below SQL query to linq query but I confused:

SELECT *
FROM dbo.Vahed
INNER JOIN dbo.VahedMahsol ON dbo.Vahed.VahedId = dbo.VahedMahsol.VahedId
RIGHT OUTER JOIN dbo.Mahsol ON dbo.VahedMahsol.MahsolId = dbo.Mahsol.MahsolId

I wrote this code:

vaheds =
(
  from i in db.spGetVahedByWhatWhere(what, wherestr, int.Parse(whattype), new Guid(shahrid))
  join gr in db.GorohSenfis on i.GorohSenfiId equals gr.GorohSenfiID
  join ct in db.Contacts on i.VahedId equals ct.VahedId
  join vm in db.VahedMahsols on i.VahedId equals vm.VahedId
  select i
)
.ToList();

but i don’t know how to convert

RIGHT OUTER JOIN dbo.Mahsol ON dbo.VahedMahsol.MahsolId = dbo.Mahsol.MahsolId

to linq query.

Answer 1

First of all you can rewrite your SQL query to use a LEFT OUTER JOIN instead of a RIGHT OUTER JOIN (because this is easier to convert to LINQ):

SELECT *
FROM dbo.Mahsol
LEFT OUTER JOIN dbo.VahedMahsol ON dbo.Mahsol.MahsolId = dbo.VahedMahsol.MahsolId
INNER JOIN dbo.Vahed ON dbo.VahedMahsol.VahedId = dbo.Vahed.VahedId

Now you can convert the query above in LINQ like this:

vaheds = (
  from m in db.Mahsols
  join vm1 in db.VahedMahsols on m.MahsolId equals v.MahsolId into vmgroup
  from vm in vmgroup.DefaultIfEmpty()
  join i in db.spGetVahedByWhatWhere(what, wherestr, int.Parse(whattype), new Guid(shahrid))
    on vm.VahedId equals i.VahedId
  join gr in db.GorohSenfis on i.GorohSenfiId equals gr.GorohSenfiID
  join ct in db.Contacts on i.VahedId equals ct.VahedId
  select i
).ToList();

I have no way of testing this, but I hope it works.