CODEWITHSUNDEEP
jpanullcriteria-api
tarka
tarka

Reputation: 5587

Criteria API Conditionally Evaluate 'NULL'

I have the following Criteria API query used to evaluate a given value against a number of Subject attributes.

...
    Expression literal = builder.literal((String) "%" + filterValue + "%");

    // When the globalFilter is deleted it returns ""
    if (!"".equals(filterValue)) {
        // JPQL equivilant: SELECT e FROM Subject e JOIN e.company c JOIN e.contact ct WHERE c.name LIKE :literal OR ct.firstName LIKE :literal ... etc
        List<Predicate> globalPredicate = new ArrayList<>();

        globalPredicate.add(builder.like(subject.get(Subject_.email), literal));
        globalPredicate.add(builder.like(subject.join(Subject_.contact).get(Contact_.firstName), literal));
        globalPredicate.add(builder.like(subject.join(Subject_.contact).get(Contact_.lastName), literal));
        globalPredicate.add(builder.like(subject.join(Subject_.metier).get(Metier_.name), literal));
        globalPredicate.add(builder.like(subject.join(Subject_.company).get(Company_.name), literal));

        predicates.add(builder.or(globalPredicate.toArray(new Predicate[globalPredicate.size()])));
    }
...

This creates the following query:

SELECT t1.UID AS a1, t1.EMAIL AS a2, t1.PASSWORD AS a3, t1.VERSION AS a4, t1.COMPANY_ID AS a5, t1.METIER_ID AS a6, t1.ACCOUNT_ID AS a7, t1.CONTACT_ID AS a8 FROM METIER t3, COMPANY t2, SUBJECT t1, CONTACT t0 WHERE (((((t1.EMAIL LIKE ? OR t0.FIRSTNAME LIKE ?) OR t0.LASTNAME LIKE ?) OR t3.NAME LIKE ?) OR (t2.NAME LIKE ? IS NOT NULL)) AND (((t0.ID = t1.CONTACT_ID) AND (t3.ID = t1.METIER_ID)) AND (t2.ID = t1.COMPANY_ID))) LIMIT ?, ?

The problem I am having is that the Subject_.company can be null. The query effectively ignores ALL the entries that have Subject_.company set to null.

I need to somehow modify this query so that the null values are not automatically discarded.

Upvotes: 0

Views: 194

Answers (1)

Chris
Chris

Reputation: 21145

You need to use the join method that takes a JoinType parameter, and specify JoinType.LEFT so that it uses a left outer join instead of the default. 

globalPredicate.add(builder.like(subject.join(Subject_.company, JoinType.LEFT).get(Company_.name), literal));

A left outer join will prevent the Subject->Company relation from filtering out results with null companies.

Upvotes: 2

Related Questions