从hibernate的外键表中获取主键表的结果

Question

我不熟悉休眠并尝试使用标准。 我坚持从 2 个表中获取结果，即主外键存在的表。

我有 Carpooler 和 SourceToDestinationDetails DTO，现在根据用户搜索数据，我想填充包含 SourceToDestinationDetails 的 Carpooler 对象，但我没有得到它，也不知道如何使用 Criteria API 来完成。

public class Carpooler implements Serializable{

    private long carpoolerId;
    private String drivingLicenceNumber=null;
    private String userType=null;![enter image description here][1]
    private User user=null;
    private List<VehicleDetails> listOfVehicleDetails=null;
    private List<SourceToDestinationDetails> listOfSourceToDestinationDetails=null;
    private Date carpoolerCreationDate;
}

public class SourceToDestinationDetails implements Serializable{

    private static final long serialVersionUID = -7158985673279885525L;

    private long sourceToDestinationId;
    private String sourcePlace=null;
    private String destinationPlace=null;
    private String inBetweenPlaces=null;

    private String sourceLeavingTime=null;
}

这是我写的，

Criteria criteria1 = getSession().createCriteria(SourceToDestinationDetails.class);
criteria1.add(Restrictions.like("sourcePlace", "%" + from + "%"));
criteria1.add(Restrictions.like("destinationPlace", "%" + to + "%"));
List<SourceToDestinationDetails> listOfExactMatchCarpooler = criteria1.list();  

通过上面的Criteria API，我只得到SourceToDestinationDetails DTO记录，但现在我也需要拼车记录，我不知道如何在SourceToDestinationDetails表中获取匹配Carpooler_id的拼车记录。

我的意思是如果用户给予，

String from = "Bellandur";
    String to = "Silk Board";

那么结果应该是List<Carpooler>对象，里面包含了所有匹配的SourceToDestinationDetails列表。

Answer 1

您可以通过Annotations 进行操作。您可以在 SourceToDestinationDetails 类中使用@OneToMany 注释，如下所示，

public class SourceToDestinationDetails implements Serializable{

    private static final long serialVersionUID = -7158985673279885525L;
    @Column
    private long sourceToDestinationId;
    @Column
    private String sourcePlace=null;
    @Column
    private String destinationPlace=null;
    @Column
    private String inBetweenPlaces=null;
    @Column
    private String sourceLeavingTime=null;

    @OneToMany(mappedBy = "carpooler_id", cascade = CascadeType.ALL)
    private Set<Carpooler> carpoolers;
}

如果您想使用 HIBERNATE XML 实现相同的目标。如下声明 XML

  <set name="carpoolers" table="source_destination" 
            inverse="true" lazy="true" fetch="select">
        <key>
            <column name="carpooler_id" not-null="true" />
        </key>
        <one-to-many class="com.test.Carpooler" />
    </set>

在这种情况下，您的模型类将是

public class SourceToDestinationDetails implements Serializable{

    private static final long serialVersionUID = -7158985673279885525L;

    private long sourceToDestinationId;
    private String sourcePlace=null;
    private String destinationPlace=null;
    private String inBetweenPlaces=null;

    private String sourceLeavingTime=null;
    private Set<StockDailyRecord> carpoolers = 
                new HashSet<StockDailyRecord>();
}

比起丑陋的 XML，我通常更喜欢注解