Criteria search needs help

Cemil · **Joined:** Thu Nov 16, 2006 12:42 pm **Posts:** 7

Hi all,

I need help on a criteria i am trying to add to make a query.

I have these two objects, Policy and Product:

Code:

public class Policy {

   private int id;

   private Product product;

   private int conversionAttempts;

       ...
}

public class Product{

   private int id;

   private Date creationDate;

       ...
}

This is my mapping for the relation between the two objects:

Code:

  <class name="Policy" table="policy_status">
     <id name="id" type="int" column="policy_status_id">
    <property name="conversionAttempts" column="conversion_attempts" />
    <many-to-one name="product" column="product_scheme_id" class="Product" lazy="false" cascade="none" not-null="true" /> 

And i also have the mapping of the Product which contains a creation date.

I am then trying to add the following expression:
criteria.add(Expression.eq("product.creationDate", date));

But it fails complaining that it does not know the property product.creationDate.

And i am 100% sure that it is not a spelling error.

Apparently the creation date is not known for the Policy, only the whole product object is.

How can i add a criteria where i want all the Policies, that have a certain product creation date ?

Hope someone has the answer.

Best Regards
Cemil[/b]

andresgr · **Posted:** Thu Nov 30, 2006 5:40 am

Here you can find an example of what you want:

http://www.hibernate.org/hib_docs/v3/re ... sociations

" You may easily specify constraints upon related entities by navigating associations using createCriteria()."

Cemil · **Joined:** Thu Nov 16, 2006 12:42 pm **Posts:** 7

Hi andresgr

That was brilliant.

Thanks for the swift answer, i made it work now.

The solution was:
criteria.createCriteria("product").add(Restrictions.eq("creationDate", date));

I have only small question left.

When should i use Expression and when should i use Restrictions ?

What is the difference

Best Regards
Cemil

andresgr · **Posted:** Thu Nov 30, 2006 6:03 am

From the javadoc:

http://www.hibernate.org/hib_docs/v3/ap ... ssion.html

This class is semi-deprecated. Use Restrictions.

Please, if my answers did help, rate them :)

Cemil · **Joined:** Thu Nov 16, 2006 12:42 pm **Posts:** 7

Hi andresgr,

Sorry about the rating.

I rated it just now.

And thanks for the answer about the deprecation as well...

Have nice day.

Best Regards Cemil