It might look like :
var qry = (from a in MasterTitles
join d in TitleDetails on a.MyID equals d.MyID into grp
from g in grp.DefaultIfEmpty()
select new
{
MyID = a.MyID,
Title = grp != null ? string.Concat(a.Title, " *") : string.Empty
}).Distinct();
For further information, please see:
How to: Perform Left Outer Joins (C# Programming Guide)[
^]