I am new to GAE and especially for Datastore (JDO)
I have an Object Composition : User object has a reference of Contact object. I am able to store them in datastore. But the code allows to store multiple objects with same “username” which is defined as primary key.
Here is the code snippet
//User class
@PersistenceCapable (identityType = IdentityType.APPLICATION)
public class User{
@PrimaryKey
@Persistent (valueStrategy = IdGeneratorStrategy.IDENTITY)
String username;
@Persistent
Contact contact;
//getters and setters
}
// Contact class
@PersistenceCapable (identityType = IdentityType.APPLICATION)
public class Contact {
@PrimaryKey
@Persistent (valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key username;
@Persistent
String Phone1;
}
//DAO class
public void register() {
User user = new User();
user.setUserName("abc");
Contact contact=new Contact();
contact.setEmail("[email protected]");
user.setContact(contact);
pm.makePersistent(user);
}
If I call this register method twice (or equivalent to submit a registration form twice with same set of username and email id), the datastore is not complaining about duplicate key Exception.
Since I am creating "username" as my KEY I am expecting to get duplicate key Exception. But why is this not happening?
thanks Ma
