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

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(Via Annotations)
(Via XML)
Line 21: Line 21:
  
 
== Via XML ==
 
== Via XML ==
 +
<code><pre>
 +
<entity name="Employee" class="org.eclipse.testing.Employee" access="PROPERTY">
 +
  ...
 +
  <named-query name="findAllEmployeesByFirstName">
 +
    <query>SELECT OBJECT(employee) FROM Employee employee WHERE employee.firstName = :firstname</query>
 +
    <hint name="eclipselink.pessimistic-lock" value="eclipselink.pessimistic-lock">
 +
  </named-query>
 +
  ...
 +
</entity>
 +
</pre></code>

Revision as of 15:27, 15 October 2007

EclipseLink allows users the option of using pessimistic locking on their queries. This is done through the use of a query hint.

Via Annotations

@Entity
@Table(name="JPA_EMPLOYEE")
@NamedQuery(
  name="findEmployeeByPK",
  query="SELECT OBJECT(employee) FROM Employee employee WHERE employee.id = :id"),
  hints={
    @QueryHint(
      name=EclipseLinkQueryHints.PESSIMISTIC_LOCK, 
      value=EclipseLinkQueryHints.PESSIMISTIC_LOCK)
  }
)
public class Employee implements Serializable {
...

}

Via XML

<entity name="Employee" class="org.eclipse.testing.Employee" access="PROPERTY">
  ...
  <named-query name="findAllEmployeesByFirstName">
    <query>SELECT OBJECT(employee) FROM Employee employee WHERE employee.firstName = :firstname</query>
    <hint name="eclipselink.pessimistic-lock" value="eclipselink.pessimistic-lock">
  </named-query>
  ...
</entity>