分段查询报错,java.lang.NullPointerException
执行下面方法时报错 public List<CateNews> findCateNewsByHQL(String HQL) {
Session session = null;
Query query = session.createQuery(HQL);
query.setFirstResult(0);
query.setFetchSize(7);
List list = query.list();
return list;
}
分段查询哪里错了
HQL = "FROM CateNews"
执行下面方法时报错 public List<CateNews> findCateNewsByHQL(String HQL) {
Session session = null;
Query query = session.createQuery(HQL);
query.setFirstResult(0);
query.setFetchSize(7);
List list = query.list();
return list;
}
分段查询哪里错了
HQL = "FROM CateNews"
我对于这个很模糊。
那么要什么样的session才能做这个事情呢?怎么叫不为空。
Session session = null;换成
Session session = sessionFactory.openSession();
这样session就不是null了,就可以正常使用。
值为null的变量是不能接“.”这个操作符的
select top 7 catenews0_.CATE_NEWS_ID as CATE1_3_, catenews0_.CATE_NEWS_TITLE as CATE2_3_, catenews0_.CATE_NEWS_KWORD as CATE3_3_, catenews0_.CATE_NEWS_ICON_S as CATE4_3_, catenews0_.CATE_NEWS_ICON_L as CATE5_3_, catenews0_.CATE_NEWS_ORIGIN as CATE6_3_, catenews0_.CATE_NEWS_HOT as CATE7_3_, catenews0_.CATE_NEWS_TOP as CATE8_3_, catenews0_.CATE_NEWS_AUDIT as CATE9_3_, catenews0_.CATE_NEWS_URL as CATE10_3_, catenews0_.CATE_NEWS_TIME as CATE11_3_, catenews0_.CATE_NEWS_CONTEXT as CATE12_3_, catenews0_.CATE_NEWS_TYPE_ID as CATE13_3_ from db_cate.dbo.CATE_NEWS catenews0_ order by catenews0_.CATE_NEWS_ID desc
以上是hibernate从HQL自动生成的SQL
用法如上