问题
我正在尝试从"用户"表中获取所有用户的列表,我收到以下错误:
org.hibernate.hql.internal.ast.QuerySyntaxException: users is not mapped [from users]
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)
这是我写的添加/获取用户的代码:
public List<User> getUsers() {
Session session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
List<User> result = (List<User>) session.createQuery("from users").list();
session.getTransaction().commit();
return result;
}
public void addUser(User user) {
Session session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
session.save(user);
session.getTransaction().commit();
}
public void addUser(List<User> users) {
Session session = HibernateUtil.getSessionFactory().getCurrentSession();
session.beginTransaction();
for (User user : users) {
session.save(user);
}
session.getTransaction().commit();
}
添加用户是有效的,但是当我使用getUsers函数时,我得到了这些错误。
这是我的hibernate配置文件:
<hibernate-configuration>
<session-factory>
<property name="connection.url">jdbc:mysql://localhost:3306/test</property>
<property name="connection.username">root</property>
<property name="connection.password">root</property>
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.default_schema">test</property>
<property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
<property name="show_sql">true</property>
<property name="format_sql">true</property>
<property name="hbm2ddl.auto">create-drop</property>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">1</property>
<property name="current_session_context_class">thread</property>
<!-- Mapping files will go here.... -->
<mapping class="model.Company" />
<mapping class="model.Conference" />
<mapping class="model.ConferencesParticipants" />
<mapping class="model.ConferenceParticipantStatus" />
<mapping class="model.ConferencesUsers" />
<mapping class="model.Location" />
<mapping class="model.User" />
</session-factory>
这是我的用户类:
@Entity
@Table( name = "Users" )
public class User implements Serializable{
private long userID;
private int pasportID;
private Company company;
private String name;
private String email;
private String phone1;
private String phone2;
private String password; //may be null/empty , will be kept hashed
private boolean isAdmin;
private Date lastLogin;
User() {} //not public on purpose!
public User(int countryID, Company company, String name, String email,
String phone1, String phone2, String password, boolean isAdmin) {
this.pasportID = countryID;
this.company = company;
this.name = name;
this.email = email;
this.phone1 = phone1;
this.phone2 = phone2;
this.password = password;
this.isAdmin = isAdmin;
}
@Id
@GeneratedValue(generator="increment")
@GenericGenerator(name="increment", strategy = "increment")
public long getUserID() {
return userID;
}
public void setUserID(long userID) {
this.userID = userID;
}
...
}
知道为什么我会收到此错误吗?
#1 热门回答(236 赞)
在HQL中,你应该使用java类名称和属性名称of mapped@Entity
而不是实际的表名和列名,因此HQL应该是:
List<User> result = (List<User>) session.createQuery("from User").list();
#2 热门回答(21 赞)
例如:你的bean类名称是UserDetails
Query query = entityManager. createQuery("Select UserName from**UserDetails**");
你没有在Db.上给出你的表名,你给出了bean的类名。
#3 热门回答(12 赞)
只是为了分享我的发现。即使查询的目标是正确的类名,我仍然会遇到相同的错误。后来我意识到我从错误的包中导入了Entity类。
我从以下位置更改导入行后问题得以解决:
import org.hibernate.annotations.Entity;
至
import javax.persistence.Entity;