How to use LINQ Distinct() with multiple fields

Question

I have the following EF class derived from a database (simplified)

class Product
{ 
     public string ProductId;
     public string Product         


        

Answer 1

public List GetBrandListByCat(int id)
    {

        var OBJ = (from a in db.Items
                   join b in db.Brands on a.BrandId equals b.Id into abc1
                   where (a.ItemCategoryId == id)
                   from b in abc1.DefaultIfEmpty()
                   select new
                   {
                       ItemCategoryId = a.ItemCategoryId,
                       Brand_Name = b.Name,
                       Brand_Id = b.Id,
                       Brand_Pic = b.Pic,

                   }).Distinct();


        List ob = new List();
        foreach (var item in OBJ)
        {
            ItemCustom2 abc = new ItemCustom2();
            abc.CategoryId = item.ItemCategoryId;
            abc.BrandId = item.Brand_Id;
            abc.BrandName = item.Brand_Name;
            abc.BrandPic = item.Brand_Pic;
            ob.Add(abc);
        }
        return ob;

    }