Update Row if it Exists Else Insert Logic with Entity Framework

Question

Does anyone have suggestions on the most efficient way to implement "update row if it exists else insert" logic using Entity Framework?

Answer 1

If you are working with attached object (object loaded from the same instance of the context) you can simply use:

if (context.ObjectStateManager.GetObjectStateEntry(myEntity).State == EntityState.Detached)
{
    context.MyEntities.AddObject(myEntity);
}

// Attached object tracks modifications automatically

context.SaveChanges();

If you can use any knowledge about the object's key you can use something like this:

if (myEntity.Id != 0)
{
    context.MyEntities.Attach(myEntity);
    context.ObjectStateManager.ChangeObjectState(myEntity, EntityState.Modified);
}
else
{
    context.MyEntities.AddObject(myEntity);
}

context.SaveChanges();

If you can't decide existance of the object by its Id you must exectue lookup query:

var id = myEntity.Id;
if (context.MyEntities.Any(e => e.Id == id))
{
    context.MyEntities.Attach(myEntity);
    context.ObjectStateManager.ChangeObjectState(myEntity, EntityState.Modified);
}
else
{
    context.MyEntities.AddObject(myEntity);
}

context.SaveChanges();