Use a filter in an outer join in linq

Question

I have the following entities:

public class Company
    {
        public string CompanyName { get; set; }
        public int ID { get; set; }
    }

public c         


        

Answer 1

You need to either apply the filter before the join:

join cc in CompanyCurrency.Where(e => e.CompanyId == 1)

or as part of the join

on new { CurrencyId = c.ID, CompanyId = 1 } equals new { cc.CurrencyId, cc.CompanyId }

For inner joins it doesn't really matter, but for outer join it's important (the same btw applies to SQL queries).