public void EditWithConflict()
{
using (var db = new TagLocsDbContext())
{
var location = db.Locations.Single(p => p.LocationId == 1);
location.Tags = db.Tags.ToList();
db.SaveChanges(); //Conflict - will throw an exception
}
}
public void Create()
{
using (var db = new TagLocsDbContext())
{
db.Locations.Add(new Location {
Tags = db.Tags.Where(p => p.TagId == 2).ToList()
});
db.SaveChanges(); // correctly saves the new location with TagId 2 attached
}
}
private static void PrintLocation(string afterCreate, int i)
{
Console.WriteLine(afterCreate);
using (var db = new TagLocsDbContext())
{
var location = db.Locations.Single(a => a.LocationId == i);
var tags = string.Join(",", location.Tags.Select(a => a.TagId));
Console.WriteLine("Location {0} : Tags {1}", location.LocationId, tags);
}
}
public void Edit(bool clear)
{
using (var db = new TagLocsDbContext())
{
var location = db.Locations.Single(p => p.LocationId == 1);
if (clear)
{
location.Tags.Clear();
}
location.Tags = db.Tags.Where(p => p.TagId == 1).ToList();
db.SaveChanges(); // if Clear ran locations = {1}, otherwise it is {1,2}
}
}
