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

from l in context.Projects.Where(w => w.Year <= 2001 )
        group l by l.DeptId into depts
        select depts.LastOrDefault();

Lambda version:

    context.Projects.Where(w => w.Year <= 2001)
        .GroupBy(g => g.DeptId)
        .Select (s => s.LastOrDefault());

Or alternatively:

    context.Projects.Where(w => w.Year <= 2001)
        .GroupBy(g => g.DeptId)
        .Select (s => s.OrderBy(o => o.Year).LastOrDefault());

Answer 2

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();