ASP.NET Core & EntityFramework Core: Left (Outer) Join in Linq

Question

I am trying to get a left join working in Linq using ASP.NET Core and EntityFramework Core.

Simple situation with two tables:

Person (id, firstname, lastnam

Answer 1

I agree to author of this post - it is still look like a bug! If you have empty joined tables you always receive "Object reference not set to an instance of an object.". The only way is to check joined tables to null:

    IEnumerable clubServices =
        from s in services
        from c in clubs.Where(club => club.ClubId == s.ClubId).DefaultIfEmpty()
        from t in clubs.Where(tenant => tenant.TenantId == c.TenantId).DefaultIfEmpty()
        select new Models.Service
        {
            ServiceId = s.ServiceId.ToString(),
            ClubId = c == null ? (int?)null : c.ClubId,
            ClubName = c == null ? null : c.Name,
            HasTimeTable = s.HasTimeTable,
            MultipleCount = s.MultipleCount,
            Name = s.Name,
            Tags = s.Tags.Split(';', StringSplitOptions.RemoveEmptyEntries),
            TenantId = t == null ? (int?)null : t.TenantId,
            TenantName = t == null ? null : t.Name
        };

I unable to check "detailText = person.PersonDetails.Select(d => d.DetailText).SingleOrDefault()" because my joined tables are in different DB.