Difference between revisions of "EclipseLink/Examples/JPA/DatabaseQuery"

Latest revision as of 16:13, 25 November 2009

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

See:

org.eclipse.persistence.queries
org.eclipse.persistence.expressions
Queries in the EclipseLink User's Guide

Using JpaEntityManager createQuery() API

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();

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

@@ Line 1: / Line 1: @@
+[[Category:EclipseLink/Example/JPA|DatabaseQuery]]
 In addition to JPQL, EclipseLink defines a rich DatabaseQuery and Expression criteria API.
@@ Line 9: / Line 11: @@
 <source lang="java">
 import javax.persistence.Query;
-import org.eclipse.persistence.expression.*;
+import org.eclipse.persistence.expressions.*;
 import org.eclipse.persistence.queries.ReadAllQuery;