Hello all,

I have a dude about the use of ORMs in general, in this case Hibernate ;)

Well, supose we have a two persistent class

Person.java

Long id;
String name;
String surname;
Country country;

Country.java

Long id;
String name


then when a user click in my creator form we recibe parameters

name, surname, countryId (from a combobox)

MY QUESTION:

Is necessary to find first for Country and when we have the object reference persist person?

Actually in SQL is sufficient with these 3 parameters an the person id is auto_increment in mysql for example

So in resume, is necesary all the data in country when we really insert a row in person table ONLY

Thanks in advance

kodaky

Hi kodaky,

I think you're looking for something like the following:



If you use session.get(..), then the Country object will be queried out. If you use session.load(..), however, you're actually getting a proxy-subclass of the Country class, with properties unset. These properties are "lazily" set, meaning that the full Country object will be queried out only-if and not-until you try to access a property of it (e.g. country.getName()).

Thus, the above code will only insert into the Person table (including the countryId foreign key), and not query the Country table.

-- Jim Steinberger