如何使用返回参数从Hibernate调用Oracle函数？

Question

我的问题非常类似于通过Hibernate获取PL/SQL函数的返回值

我有一个函数在内部进行一些修改,它返回一个值.

最初的想法是做这样的事情:

protected Integer checkXXX(Long id, Long transId)
        throws Exception {
    final String sql = "SELECT MYSCHEMA.MYFUNC(" + id + ", "
            + transId + ") FROM DUAL";
    final BigDecimal nr = (BigDecimal) this.getHibernateTemplate()
            .getSessionFactory().getCurrentSession().createSQLQuery(sql)
            .uniqueResult();
    return nr.intValue();
}

不幸的是,这不适用于Oracle.做这样的事情的推荐方法是什么？

有没有办法从我的语句中提取声明的变量？

Answer 1

Hibernate Session提供了一种doWork()方法,可让您直接访问java.sql.Connection.然后,您可以创建并使用它java.sql.CallableStatement来执行您的功能:

session.doWork(new Work() {
  public void execute(Connection connection) throws SQLException {
    CallableStatement call = connection.prepareCall("{ ? = call MYSCHEMA.MYFUNC(?,?) }");
    call.registerOutParameter( 1, Types.INTEGER ); // or whatever it is
    call.setLong(2, id);
    call.setLong(3, transId);
    call.execute();
    int result = call.getInt(1); // propagate this back to enclosing class
  }
});

Answer 2

我写了一篇关于从Hibernate调用Oracle存储过程和函数的各种方法的文章,所以总结一下,你有以下几种选择:

1. 用@NamedNativeQuery:

   @org.hibernate.annotations.NamedNativeQuery(
       name = "fn_my_func",
       query = "{ ? = call MYSCHEMA.MYFUNC(?, ?) }",
       callable = true,
       resultClass = Integer.class
   )
   
   Integer result = (Integer) entityManager.createNamedQuery("fn_my_func")
       .setParameter(1, 1)
       .setParameter(2, 1)
       .getSingleResult();    
   

2. 使用JDBC API:

   Session session = entityManager.unwrap( Session.class );
   
   final AtomicReference<Integer> result = 
       new AtomicReference<>();
   
   session.doWork( connection -> {
       try (CallableStatement function = connection
               .prepareCall(
                   "{ ? = call MYSCHEMA.MYFUNC(?, ?) }"
               )
           ) {
           function.registerOutParameter( 1, Types.INTEGER );
           function.setInt( 2, 1 );
           function.setInt( 3, 1 );
           function.execute();
           result.set( function.getInt( 1 ) );
       }
   } );            
   

3. 使用本机Oracle查询:

   Integer result = (Integer) entityManager.createNativeQuery(
       "SELECT MYSCHEMA.MYFUNC(:postId, :transId) FROM DUAL")
       .setParameter("postId", 1)
       .setParameter("transId", 1)
       .getSingleResult();
   

Answer 3

是的,您确实需要使用out参数.如果你使用doWork()方法,你会做这样的事情:

session.doWork(new Work() {
   public void execute(Connection conn) {
      CallableStatement stmt = conn.prepareCall("? = call <some function name>(?)");
      stmt.registerOutParameter(1, OracleTypes.INTEGER);
      stmt.setInt(2, <some value>);
      stmt.execute();
      Integer outputValue = stmt.getInt(1);
      // And then you'd do something with this outputValue
   }
});

Answer 4

备用代码:)

如果要直接结果，可以使用以下代码

 int result = session.doReturningWork(new ReturningWork<Integer>() {
  @Override
   public Integer  execute(Connection connection) throws SQLException {
    CallableStatement call = connection.prepareCall("{ ? = call MYSCHEMA.MYFUNC(?,?) }");
    call.registerOutParameter( 1, Types.INTEGER ); // or whatever it is
    call.setLong(2, id);
    call.setLong(3, transId);
    call.execute();
    return call.getInt(1); // propagate this back to enclosing class
  }
});

http://keyurj.blogspot.com.tr/2012/12/dowork-in-hibernate.html