Using TObjectManager you can save (insert) objects using Save method. It is analog to SQL INSERT statement - it saves the object in database.
Customer1 := TCustomer.Create;
Customer1.Name := 'John Smith';
Customer1.Sex := tsMale;
Customer1.Birthday := EncodeDate(1986, 1, 1);
The identifier of the object (mapped using Id attribute) must not have a value, otherwise an exception will be raised - unless the generator defined in Id attribute is TIdGenerator.None. In this case, you must manually provide the id value of the object, and so of course Aurelius will accept an object with an id value. But you must be sure that there are no objects in the database with the same id value, to avoid duplicate values in the primary key.
When saving an object, associations and items in collections might be saved as well, depending on how cascade options are set when you defined the Association and ManyValuedAssociation attribute. In the example below, customer is defined to have SaveUpdate cascade. It means that when invoice is saveed, the customer is saved as well, before the invoice.
Customer := TTC_Customer.Create;
Customer.Name := 'Customer Name';
Invoice := TTC_Invoice.Create;
Invoice.InvoiceType := 999;
Invoice.InvoiceNo := 123456;
Invoice.Customer := Customer;
Invoice.IssueDate := Date;
You can also use SaveOrUpdate method to save objects. The difference from Save is that if the object has an id value set, SaveOrUpdate will internally call Update method instead of Save method. So, if you use TIdGenerator.None in the Id attribute of your object class, SaveOrUpdate will not work.