c# - InsertAllOnSubmit only inserts first data record

Question

I noticed a strange behaviour in my Import Service today when I tried to import multiple data records.

When I do it like this, all data records are imported and the auto-incremented value is correct (see screenshot):

public void Create(List<Property> properties)
{
    foreach (Property prop in properties) {
        dbc.Property.InsertOnSubmit(prop);
        dbc.SubmitChanges();
    }
}

When I try it like this, only the first data record get's a correct auto-incremented value (see screenshot):

foreach (Property prop in properties) {
    dbc.Property.InsertOnSubmit(prop);
}
dbc.SubmitChanges();

Same here:

dbc.Property.InsertAllOnSubmit(properties);
dbc.SubmitChanges();

Does anybody have an idea why it's like that? All three variants should import all data records according to my understanding, but the missing auto-incremented values indicate it's not that way.

[EDIT] Added two screenshots.

Answer 1

I had the same problem and it turned out the issue was due to overriding Equals on the mapped class. My Equals method was only comparing the primary key field which was an identity field. Of course when the objects are new, all identities are 0. So when InsertAllOnSubmit was called, it thought that all new objects were the same and basically ignored every one but the first.