使用Hibernate出现过的异常总结

来源：互联网发布：淘宝虚假交易清洗过3次编辑：程序博客网时间：2024/06/07 20:21

1.在根据ID查询用户信息时报了如下错误，

java.lang.NullPointerExceptionat org.hibernate.hql.internal.ast.util.SessionFactoryHelper.findSQLFunction(SessionFactoryHelper.java:364)at org.hibernate.hql.internal.ast.tree.IdentNode.getDataType(IdentNode.java:319)at org.hibernate.hql.internal.ast.tree.SelectClause.initializeExplicitSelectClause(SelectClause.java:152)at org.hibernate.hql.internal.ast.HqlSqlWalker.useSelectClause(HqlSqlWalker.java:859)

后来根据分析错误原因是hql写的不对，

错误的写法是：

public User getUser(String id) {String hql = "select User from User u where u.id = ?";Query query = sessionFactory.getCurrentSession().createQuery(hql);query.setString(0, id);User user = (User) query.uniqueResult();return user;}

正确的写法是：

public User getUser(String id) {String hql = "from User u where u.id = ?";Query query = sessionFactory.getCurrentSession().createQuery(hql);query.setString(0, id);User user = (User) query.uniqueResult();return user;}

hql中加上"select User"是错误的原因。删掉以后就没问题了。

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