Hibernate错误 - QuerySyntaxException:用户未映射[来自用户]

Question

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,我收到了这些错误.

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User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这个错误吗？

Answer 1

在HQL中,您应该使用映射的java类名和属性名@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();

Answer 2

例如:您的bean类名称是UserDetails

Query query = entityManager. createQuery("Select UserName from **UserDetails** "); 

您没有在Db上提供您的表名.你给bean的类名.

Answer 3

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.

更改导入行后,问题解决了:

import org.hibernate.annotations.Entity;

至

import javax.persistence.Entity;

Answer 4

添加了@TABLE(name = "TABLE_NAME")注释并修复了.检查您的注释和hibernate.cfg.xml文件.这是有效的示例实体文件:

import javax.persistence.*;

@Entity
@Table(name = "VENDOR")
public class Vendor {

    //~ --- [INSTANCE FIELDS] ------------------------------------------------------------------------------------------
    private int    id;
    private String name;

    //~ --- [METHODS] --------------------------------------------------------------------------------------------------
    @Override
    public boolean equals(final Object o) {    
        if (this == o) {
            return true;
        }

        if (o == null || getClass() != o.getClass()) {
            return false;
        }

        final Vendor vendor = (Vendor) o;

        if (id != vendor.id) {
            return false;
        }

        if (name != null ? !name.equals(vendor.name) : vendor.name != null) {
            return false;
        }

        return true;
    }

    //~ ----------------------------------------------------------------------------------------------------------------
    @Column(name = "ID")
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Id
    public int getId() {
        return id;
    }

    @Basic
    @Column(name = "NAME")
    public String getName() {

        return name;
    }

    public void setId(final int id) {
        this.id = id;
    }

    public void setName(final String name) {    
        this.name = name;
    }

    @Override
    public int hashCode() {
        int result = id;
        result = 31 * result + (name != null ? name.hashCode() : 0);
        return result;
    }
}

Answer 5

您可能忘记将创建的实体的映射添加到hibernate.cfg.xml，同样的错误。

Answer 6

org.hibernate.hql.internal.ast.QuerySyntaxException: users is not mapped [from users]

这表明hibernate不知道该User实体是"用户".

@javax.persistence.Entity
@javax.persistence.Table(name = "Users")
public class User {

该@Table注释设置表的名称是"用户",但实体名称仍然指在HQL"用户".

要更改两者,您应该设置实体的名称:

// this sets the name of the table and the name of the entity
@javax.persistence.Entity(name = "Users")
public class User implements Serializable{

有关详细信息,请参阅此处的答案:Hibernate表未映射错误

Answer 7

另请检查您是否使用以下命令添加了带注释的类：

new Configuration().configure("configuration file path").addAnnotatedClass(User.class)

使用 Hibernate 在数据库中添加新表时，这总是浪费我的时间。

Answer 8

还要确保在hibernate bean配置中设置了以下属性:

<property name="packagesToScan" value="yourpackage" />

这告诉spring和hibernate在哪里找到注释为实体的域类.

Answer 9

一些基于Linux的MySQL安装需要区分大小写.解决方法是申请nativeQuery.

@Query(value = 'select ID, CLUMN2, CLUMN3 FROM VENDOR c where c.ID = :ID', nativeQuery = true)