org.hibernate.hql.ast.QuerySyntaxException: is not mapped 异常总结
程序运行出现如下问题
org.hibernate.hql.ast.QuerySyntaxException: User is not mapped [select u from User u where u.userName=:userName and u.password=:password]
at org.hibernate.hql.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:158)at org.hibernate.hql.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:87)
at org.hibernate.hql.ast.tree.FromClause.addFromElement(FromClause.java:70)
at org.hibernate.hql.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:257)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3056)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:2945)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:688)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:544)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:281)
at org.hibernate.hql.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:229)
at org.hibernate.hql.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:228)
at org.hibernate.hql.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:160)
at org.hibernate.hql.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:111)
at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:77)
at org.hibernate.engine.query.HQLQueryPlan.<init>(HQLQueryPlan.java:56)
at org.hibernate.engine.query.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:72)
at org.hibernate.impl.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:133)
at org.hibernate.impl.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:112)
at org.hibernate.impl.SessionImpl.createQuery(SessionImpl.java:1623)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.hibernate.context.ThreadLocalSessionContext$TransactionProtectionWrapper.invoke(ThreadLocalSessionContext.java:301)
at $Proxy0.createQuery(Unknown Source)
at org.kf.dao.impl.UserDaoImpl.userLogin(UserDaoImpl.java:40)
at org.kf.biz.UserBiz.userLogin(UserBiz.java:19)
at test.Test.main(Test.java:13)
上面的异常的抛出主要有几个方面：
1、最容易想到的，就是你的from是实体类而不是表名，这个应该大家都知道，注意大小写
2、你的hibernate配置文件中没有加入相应的映射文件<mapping resource=" " />
3、如果上面两方面都对了，还有错，基本上处于崩溃状态，哈哈....一般是上面两种原因，还是不行，那就是你hql语句有错了，好好检查一下，仔细点，不行就重新写一遍，因为我就是因为一个中文空格被折腾了两天啊，就是找不出哪儿出错了，怎么看怎么对，可是就是报错，哈哈...很崩溃的。所以要记住HQL中查询的时实体类查询，而不是用表名查询的哦。