Using Linq to find duplicates but get the whole record

Question

So I am using this code

    var duplicates = mg.GroupBy(i => new { i.addr1, i.addr2 })
                    .Where(g => g.Count() > 1)
                          


        

Answer 1

You should use First() instead of Key:

var duplicates = mg.GroupBy(i => new { i.addr1, i.addr2 })
                .Where(g => g.Count() > 1)
                .Select(g => g.First());

It returns the first row of each duplicate groups

Answer 2

To get all values, you can use ToList() on IGrouping

var duplicates = mg.GroupBy(i => new { i.addr1, i.addr2 })
                   .Where(g => g.Count() > 1)
                   .Select(g => new {g.Key, Values = g.ToList()});