如何使用Hibernate获取只有一列的值

我刚开始使用Hibernate进行开发，并在尝试选择表格中的列时遇到问题。我有一个名为“Nome”的列，它是一个字符串。我想要做的就是在我的表格中获取此列的所有值。为此，我已经创建的方法：如何使用Hibernate获取只有一列的值

public List<String> obtemNomePorQuery(String query) { 

     EntityManager manager = getEntityManager(); 

     Session session = manager.unwrap(Session.class);  

     List<String> listResult = (List<String>) session.createQuery(query).list(); 
     manager.close(); 

     return listResult; 
    }

在这种情况下，我传递查询参数“中选择从lojas诺姆”。在MySQL中，我可以运行这个查询，它返回我想要的所有东西。使用休眠我得到以下日志：

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.hibernate.hql.internal.ast.QuerySyntaxException: lojas is not mapped [select nome from lojas] 
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:656) 
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549) 
    javax.servlet.http.HttpServlet.service(HttpServlet.java:621) 
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728) 
root cause 

org.hibernate.hql.internal.ast.QuerySyntaxException: lojas is not mapped [select nome from lojas] 
    org.hibernate.hql.internal.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:180) 
    org.hibernate.hql.internal.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:110) 
    org.hibernate.hql.internal.ast.tree.FromClause.addFromElement(FromClause.java:93) 
    org.hibernate.hql.internal.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:326) 
    org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3252) 
    org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3141) 
    org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:694) 
    org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:550) 
    org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:287) 
    org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:235) 
    org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:248) 
    org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:183) 
    org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:136) 
    org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:101) 
    org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:80) 
    org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:119) 
    org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:214) 
    org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:192) 
    org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1537) 
    com.puccamp.projetofinal.persistence.Dao.obtemNomePorQuery(Dao.java:198) 
    com.puccamp.projetofinal.controller.LojaController.gerenciaLoja(LojaController.java:63) 
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 
    sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) 
    sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) 
    java.lang.reflect.Method.invoke(Unknown Source) 
    org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:176) 
    org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:426) 
    org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:414) 
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790) 
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719) 
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644) 
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:549) 
    javax.servlet.http.HttpServlet.service(HttpServlet.java:621) 
    javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

我该怎么做错了？

来源

2013-05-04 Felipe Mosso

您正在使用的方法需要HQL而不是SQL。是否有与lojas表关联的持久对象？如果不是HQL不是您的选择，您需要改为获得与数据库的本地连接以执行SQL。您是否尝试过Session的createSQLQuery(String queryString)方法？这里是javadoc：http://docs.jboss.org/hibernate/orm/3.5/javadoc/org/hibernate/Session.html

来源

2013-05-04 00:20:02

谢谢！我只是使用createSQLQuery方法，并按我期望的那样工作！ – 2013-05-04 00:30:28

如何使用Hibernate获取只有一列的值

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