What would be the query for:
select s.* from Service s
inner join ServiceAssignment sa on sa.ServiceId = s.Id
where sa.LocationId = 1
in
from s in db.Services
join sa in db.ServiceAssignments on s.Id equals sa.ServiceId
where sa.LocationId == 1
select s
Where db is your DbContext. Generated query will look like (sample for EF6):
SELECT [Extent1].[Id] AS [Id]
-- other fields from Services table
FROM [dbo].[Services] AS [Extent1]
INNER JOIN [dbo].[ServiceAssignments] AS [Extent2]
ON [Extent1].[Id] = [Extent2].[ServiceId]
WHERE [Extent2].[LocationId] = 1