如何在jpa中编写订单并限制查询


问题内容

我希望在编写以下查询时基于表’MasterScrip’的’totalTradedVolume’获取前10个结果:

Collection<MasterScrip> sm=null;
   sm=em.createQuery("select m from MasterScrip m where m.type = :type order by m.totalTradedVolume limit 2").setParameter("type", type).getResultList();

我得到以下异常:

Caused by: java.lang.IllegalArgumentException: An exception occurred while creating a query in EntityManager: 
Exception Description: Syntax error parsing the query [select m from MasterScrip m where m.type = :type order by m.totalTradedVolume limit 2], line 1, column 78: unexpected token [limit].
Internal Exception: NoViableAltException(80@[])

我的jpa查询有问题。有人可以纠正我吗?


问题答案:

limit在JPA中不被认可。您可以改用以下query.setMaxResults方法:

sm = em.createQuery("select m from MasterScrip m where m.type = :type 
        order by m.totalTradedVolume")
    .setParameter("type", type)
    .setMaxResults(2).getResultList()