Hibernate使用条件或hql查询/实时处理多个表

Question

我是Hibernate的新手，希望实现Hibernate条件或hql来查询多个表以获得结果，但我在这方面遇到了问题。。现在，我在hibernate中使用原生sql来完成我需要的任务，但我想用hql/criteria尝试一下。。下面是我用来获取结果的本机查询。。

select table1.dmname,table2.polname,table3.path,table4.uidname 
    from table1,table2,table3,table4
    where table3.dmnid = table1.dmnid
    and table3.polid = table2.polid
    and table3.3.uid = table4.uid

下面是我的实体pojo类

表1：

@Entity
@Table(name = "table1", uniqueConstraints = @UniqueConstraint(columnNames = "dmname"))
        @Cache(usage=CacheConcurrencyStrategy.READ_ONLY,region="domain")
public class table1  {

    private String dmnid;
    private String dmnname;

    @Id
    @Column(name = "dmnid", unique = true, nullable = false)
    public String getDmnid() {
        return this.dmnid;
    }

    public void setDmnid(String dmnid) {
        this.dmnid = dmnid;
    }

    @Column(name = "dmnname", unique = true, nullable = false)
    public String getDmnname() {
        return this.dmnname;
    }

    public void setDmnname(String dmnname) {
        this.dmnname = dmnname;
    }

表2：

@Entity
@Table(name = "table2", uniqueConstraints = @UniqueConstraint(columnNames = {
        "dmnname", "polname" }))
public class table2 implements java.io.Serializable {

    private String dmnname;
    private String polid;
    private String polname;

    // getters and setter

表3：

@Entity
@Table(name = "table3")
public class table3 implements java.io.Serializable {

    private String dmnname;
    private String polid;
    private String uid;
    private String path;

    // getters and setters

表4：

@Entity
@Table(name = "table4", uniqueConstraints = @UniqueConstraint(columnNames = "uidname"))
public class table4 implements java.io.Serializable {

    private String uid;
    private String uidname;

    // getters and setters

我还没有实现pojo类中表之间的映射，我很难理解这一点。。所以我要向社区寻求帮助来救我。。感谢您的关注，我们将非常感谢您的帮助。。

Answer 1

我建议你参考这里的Hibernate文档来详细了解关联。http://docs.jboss.org/hibernate/orm/5.2/userguide/html_single/Hibernate_User_Guide.html#associations

关于您在HQL上的问题，转换您的本机SQL（除非您需要任何明确的连接条件）看起来像这样：

  Query query = session.createQuery('from table1 t1,table2 t2,table3 t3,table4 t4
        where t3.dmnid = t1.dmnid
        and t3.polid = t2.polid
        and t3.uid = t4.uid');
  List results = query.list();