hibernate table is not mapped [from table]

使用hibernate、spring框架，进行数据库操作时，出现如下错误：

 Exception in thread "main" org.hibernate.hql.internal.ast.QuerySyntaxException: order is not mapped [from order where orderId=?]
	at org.hibernate.hql.internal.ast.util.SessionFactoryHelper.requireClassPersister(SessionFactoryHelper.java:180)
	at org.hibernate.hql.internal.ast.tree.FromElementFactory.addFromElement(FromElementFactory.java:110)
	at org.hibernate.hql.internal.ast.tree.FromClause.addFromElement(FromClause.java:93)
	at org.hibernate.hql.internal.ast.HqlSqlWalker.createFromElement(HqlSqlWalker.java:324)
	at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElement(HqlSqlBaseWalker.java:3420)
	at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromElementList(HqlSqlBaseWalker.java:3309)
	at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.fromClause(HqlSqlBaseWalker.java:706)
	at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.query(HqlSqlBaseWalker.java:562)
	at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.selectStatement(HqlSqlBaseWalker.java:299)
	at org.hibernate.hql.internal.antlr.HqlSqlBaseWalker.statement(HqlSqlBaseWalker.java:247)
	at org.hibernate.hql.internal.ast.QueryTranslatorImpl.analyze(QueryTranslatorImpl.java:250)
	at org.hibernate.hql.internal.ast.QueryTranslatorImpl.doCompile(QueryTranslatorImpl.java:185)
	at org.hibernate.hql.internal.ast.QueryTranslatorImpl.compile(QueryTranslatorImpl.java:138)
	at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:105)
	at org.hibernate.engine.query.spi.HQLQueryPlan.<init>(HQLQueryPlan.java:80)
	at org.hibernate.engine.query.spi.QueryPlanCache.getHQLQueryPlan(QueryPlanCache.java:168)
	at org.hibernate.internal.AbstractSessionImpl.getHQLQueryPlan(AbstractSessionImpl.java:221)
	at org.hibernate.internal.AbstractSessionImpl.createQuery(AbstractSessionImpl.java:199)
	at org.hibernate.internal.SessionImpl.createQuery(SessionImpl.java:1778)
	at dao.impl.OrderDao.getOrderById(OrderDao.java:24)
	at service.impl.OrderItemService.createOrderItem(OrderItemService.java:21)
	at second.testOrder.main(testOrder.java:21)

错误原因：因为在OrderDao.java中使用的是hql语句，所以应该使用实体类名而不是数据库表名。

这个例子中，我将OrderDao.java中的“from order where orderId=？”改为“from Order where orderId=？”后，问题便解决了。

转载于:https://my.oschina.net/u/2329828/blog/403590