insert-update problem

[irupinax]

Environment: Mint 18.3, laz 1.8.3, fpc 3.05.

Apologies for raising this but I am trying to use ghorm and have a problem with the 'Update'. The problem may be my understanding of how to use the 'Insert' and 'Update'.
An 'update' updates the wrong record (wrong ID?) in the database.
A comment in TORM.Update(o: T) states that '// already has id,'.
I cannot see why/where and the wrong record in database is updated.

I have modified the unittest/tcUsersAndRoles to demonstrate the problem,the code is below.
Comments show the results on the record/s in the database.

So,have I got things wrong???? Any help appreciated.

Ian Upton, Melbourne Australia.

procedure TTestUsersAndRoles.TestInsertUser;
var
o: TUsers;
u: TUser;
id: Integer;
begin
o := TUsers.Create;

u := o.New;
u.Name := 'Mario';
u.Password := '123abc';
AssertTrue('Failed to insert user to database',o.Insert(u));
id := u.ID;
u.Free; // Mario123abc <<<< Record in DB

u := o.New;
u.Name := 'iru';
u.Password := '123';
AssertTrue('Failed to insert iru to database',o.Insert(u));
id := u.ID;
// u.Free; // iru123 Mario123abc <<<< Two records in DB

u.Password:= 'xxx';
o.Update(u); // iru123 iruxxx <<<< Wrong (?) record updated