Cannot add an entity that already exists - asp.net

Question

Code:
public ActionResult Create(Group group)
{
if (ModelState.IsValid)
{
group.int_CreatedBy = 1;
group.dtm_CreatedDate = DateTime.Now;
var Groups = Request["Groups"];
int GroupId = 0;
GroupFeature GroupFeature=new GroupFeature();
foreach (var GroupIdd in Groups)
{
// GroupId = int.Parse(GroupIdd.ToString());
}
var Features = Request["Features"];
int FeatureId = 0;
int t = 0;
int ids=0;
string[] Feature = Features.Split(',').ToArray();
//foreach (var FeatureIdd in Features)
for(int i=0; i<Feature.Length; i++)
{
if (int.TryParse(Feature[i].ToString(), out ids))
{
GroupFeature.int_GroupId = 35;
GroupFeature.int_FeaturesId = ids;
if (ids != 0)
{
GroupFeatureRepository.Add(GroupFeature);
GroupFeatureRepository.Save();
}
}
}
return RedirectToAction("Details", new { id = group.int_GroupId });
}
return View();
}
I am getting an error here Cannot add an entity that already exists. at this line GroupFeatureRepository.Add(GroupFeature);
GroupFeatureRepository.Save();

Answer 1

This line:
GroupFeature GroupFeature=new GroupFeature();
needs to be inside your for loop, like this:
for(int i=0; i<Feature.Length; i++)
{
if (int.TryParse(Feature[i].ToString(), out ids))
{
GroupFeature GroupFeature=new GroupFeature();
You need to add a new GroupFeature each time(e.g. one not in that collection, which your re-used object already is after the first loop). You can't re-use the same GroupFeature object like that for adding, but moving it inside the loop so you generate a distinct GroupFeature each time will resolve this.