NamedQuery (Java EE 5 SDK)

Java

Java EE 5 SDK

深圳电信培训中心.徐海蛟老师.


javax.persistence Annotation Type NamedQuery


@Target(value=TYPE)
@Retention(value=RUNTIME)
public @interface NamedQuery

Is used to specify a named query in the Java Persistence query language, which is a static query expressed in metadata. Query names are scoped to the persistence unit.

The following is an example of the definition of a named query in the Java Persistence query language:

    @NamedQuery(
            name="findAllCustomersWithName",
            query="SELECT c FROM Customer c WHERE c.name LIKE :custName"
    )
 

The following is an example of the use of a named query:

    @PersistenceContext
    public EntityManager em;
    ...
    customers = em.createNamedQuery("findAllCustomersWithName")
            .setParameter("custName", "Smith")
            .getResultList();
 

从以下版本开始:
Java Persistence 1.0

Required Element Summary
 String name
          Refers to the query when using the EntityManager methods that create query objects.
 String query
          The query string in the Java Persistence query language
 
Optional Element Summary
 QueryHint[] hints
          Vendor-specific query hints
 

元素详细信息

name

public abstract String name
Refers to the query when using the EntityManager methods that create query objects.


query

public abstract String query
The query string in the Java Persistence query language

hints

public abstract QueryHint[] hints
Vendor-specific query hints

默认值:
{}

Java EE 5 SDK

深圳电信培训中心.徐海蛟老师.


提交错误或意见

版权所有 2007 Sun Microsystems, Inc. 保留所有权利。 请遵守许可证条款。深圳电信培训中心.徐海蛟老师教学参考.