[C#] Example using Join Extension Method from LINQ.

linq-join-example.cs

var query = _context.TableOuter
    .Join(_context.TableInner,
    outer => outer.Id,
    inner => inner.ForeignId,
    (outer, inner) => new
    {
        outer,
        inner
    })
    .Where(x => x.inner.Property == value).Select(x => x.inner).SingleOrDefault();

var result = (InnerResult)query;