View source for EclipseLink/Examples/JPA/DatabaseQuery

[[Category:EclipseLink/Example/JPA|DatabaseQuery]]

In addition to JPQL, EclipseLink defines a rich DatabaseQuery and Expression criteria API.

See:
* [http://www.eclipse.org/eclipselink/api/1.1/org/eclipse/persistence/queries/package-frame.html org.eclipse.persistence.queries]
* [http://www.eclipse.org/eclipselink/api/1.1/org/eclipse/persistence/expressions/package-frame.html org.eclipse.persistence.expressions]
* [[EclipseLink/UserGuide/Queries_(ELUG)|Queries]] in the ''EclipseLink User's Guide''

=== Using JpaEntityManager createQuery() API ===
<source lang="java">
import javax.persistence.Query;
import org.eclipse.persistence.expressions.*;
import org.eclipse.persistence.queries.ReadAllQuery;

ExpressionBuilder builder = new ExpressionBuilder();
ReadAllQuery databaseQuery = new ReadAllQuery(Employee.class, builder);
databaseQuery.setSelectionCriteria(builder.get("firstName").like("B%"));
databaseQuery.addOrdering(builder.get("firstName").toUpperCase());

Query query = ((JpaEntityManager)entityManager.getDelegate()).createQuery(databaseQuery);
List result = query.getResultList();

</source>

This JpaEntityManager API was added in EclipseLink 1.1, in EclipseLink 1.0, the JpaQuery method setDatabaseQuery() could be used.