Linq, How to do groupBy?

Question

project table:

Id, DeptId, Year, Name, Level

Id = 1, DeptId = 1, Year = 2000, Name = \"ABC\", Level = 1
Id = 2, DeptId = 1, Year = 2001, Name = \"ABC1\",         


        

Answer 1

var query= from p in context.Projects
           group p by p.DeptId into grp
           select grp.Where(x => x.Year <= 2001)
                     .OrderByDescending(x => x.Year)
                     .FirstOrDefault();