CODEWITHSUNDEEP
hibernatehibernate-criteria
M314
M314

Reputation: 955

How to create Criteria on field that can be null?

I have to create create Criteria or Criterion on specific field myProperity (on class MyClass). I have to choose all objects that have prop = null or satisfy specific Criteria. So I should make something like:

Criteria criteria = this.sessionManager.getCurrentSession().createCriteria(MyClass.class);

specificCriteria = criteria.createCriteria('myProperity');
/* definition of specificCriteria */

Disjunction disjunction = Restrictions.disjunction();
disjunction.add(Restrictions.isNull('myProperity'));
disjunction.add(specificCriteria);

criteria.add(disjunction);

The problem is caused be the facts:

  1. I can't add Criteria to Disjunction (to Disjunction can be added only a Criterion), so line: disjunction.add(specificCriteria); is wrong
  2. I can't somehow modify the specificCriteria, to accept null because I can't make criteria on null. (It gives me NullPointerException)

Have you any Idea how to deal with it?

Upvotes: 5

Views: 45139

Answers (5)

Hitesh Gupta
Hitesh Gupta

Reputation: 1121

Restrictions.eqOrIsNull(propertyName, value) method can be used to handle null values.

Upvotes: 0

Pravin Bansal
Pravin Bansal

Reputation: 4691

Check if value provided in criteria is null by check isNull and apply to your criteria as following 

criteria.add(Restrictions.isNull("parentId"));

Upvotes: 3

DanAngelus
DanAngelus

Reputation: 71

Just for anyone else with this question. I had a similar issue where I wanted to check if an associated collection was empty and if not restrict by ID. To achieve this, the following helped me (updated code for newer version of hibernate):

Criteria criteria = getSession().createCriteria(StaffMember.class);
criteria.createAlias("franchises", "franchises", JoinType.LEFT_OUTER_JOIN)
        .add(Restrictions.or(
                Restrictions.isEmpty("franchises"),
                Restrictions.in("franchises.id", allowedFranchises)));

So this allows the following:

  1. staff members with no franchises
  2. staff members who are in a franchise with an ID from allowedFranchises collection

Upvotes: 7

David
David

Reputation: 1177

Something like this helped me:

final Criteria c = session.createCriteria(House.class)
    // Houses may not have doors.
    .createAlias("door", "door", CriteriaSpecification.LEFT_JOIN)
    // Door may be null, but if it isn't it must be blue.
    .add(Restrictions.or(Restrictions.isNull("door"), Restrictions.eq("door.color", "blue")));

This answer helped me: https://stackoverflow.com/a/2208458

Upvotes: 6

Yogesh Prajapati
Yogesh Prajapati

Reputation: 4870

You can get answer of all question here this will help you

for ex if your MyClass like

class MyClass{
   private long id;
   private String myProperity;
   .
   .
   .
   setter & getter
}

here you null issue is solved and this'll oring with other criterias.

Criteria criteria = session.createCriteria(MyClass.class);

Disjunction disjunction = Restrictions.disjunction();
disjunction.add(Restrictions.isNull("myProperity"));

criteria.add(disjunction);

criteria.add(Restrictions.eq("id", value));

Upvotes: 10

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