VB.net linq left join where null or 0 - vb.net

Question

I'm having a hard time figuring out how to do a left join and pull records where the join is null, or the join works, but the column paid is 0. This is the sql I'm trying to recreate
SELECT *
FROM JobsCompleted
LEFT JOIN SqWar ON JobsCompleted.JobFk = SqWar.JobFk
WHERE SqWar.SqWarId IS NULL OR SqWar.Paid = 0
This is what I have so far in linq
'not sure here how I do if the join is null, or joins, but paid is 0
Dim jobIds = (From jc In db.JobsCompleteds
Group Join sqw In db.SqWars On sqw.JobFk Equals jc.JobFk Into SqGroup = Group
Where jc.DateCompleted >= fromInput.SelectedDate And jc.DateCompleted <= toInput.SelectedDate And
SqGroup Is Nothing) 'not sure here how I do if it's null or paid = 0

Answer 1

With a Group Join, if you want a SQL LEFT JOIN, especially since you are wanting to test a field from the right hand side, you need to use a second From clause with DefaultIfEmpty:
Dim jobIds = From jc In db.JobsCompleteds
Group Join sqw In db.SqWars On sqw.JobFk Equals jc.JobFk Into Group
From sqw In Group.DefaultIfEmpty()
Where sqw Is Nothing Or sqw.Paid = 0
Select New With { jc, sqw }
Note that LINQ doesn't have a direct equivalent to SQL SELECT * so I returned an anonymous object with sub-objects. If you wanted the result to be flattened, you would have to explicitly list all fields.
If you wanted to process the join groups you could also filter each group by your criteria:
Dim jobIdsG = From jc In db.JobsCompleteds
Group Join sqw In db.SqWars On sqw.JobFk Equals jc.JobFk Into Group
Select New With {jc, .sqGroup = Group.Where(Function(sq) sq.Paid = 0)}