Hibernate多对多数据检索

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Hibernate many-to-many data retrieval

我有两个对象用户和联系人，具有多对多关系，我正在为这个关系 USER_CONTACT

使用中间表

在这个关联中保存数据没问题，但是检索是个问题。

我需要根据用户检索数据，但我得到的是所有用户的所有联系人。

如果你能告诉我我做错了什么就好了。

public class User {

private Integer userID;

private String userLoginEmail;

private String password;

private Set<Contact> contactSet = new HashSet<Contact>();

.

.

}



public class Contact implements Serializable {

private Integer contactID;

private String givenName;

private String familyName;

private Set<User>  userSet = new HashSet<User>();

.

.

}

<class name="User" table="USERACCOUNT">

  <id column="USER_ID" length="500" name="userID">

    <generator class="increment" />

  </id>

  <property column="USER_LOGIN_EMAIL" generated="never" lazy="false" length="100" name="userLoginEmail" />

  <property column="USER_FIRSTNAME" generated="never" lazy="false" length="100" name="userFirstName" />

  <property column="USER_LASTNAME" generated="never" lazy="false" length="100" name="userLastName" />

  <set name="contactSet" table="USER_CONTACT" inverse="false" lazy="false" fetch="select" cascade="all">

    <key column="USER_ID"/>

    <many-to-many column="CONTACT_ID" class="com.smallworks.model.Contact"/>

  </set>

</class>

<class name="Contact" table="CONTACT">

 <id column="CONTACT_ID" length="500" name="contactID">

 <generator class="increment"/>

 </id>

 <property column="GIVEN_NAME" generated="never" lazy="false" length="100" name="givenName"/>

 <property column="FAMILY_NAME" generated="never" lazy="false" length="100" name="familyName"/>



 <!-- many to many mapping with the User via User_Contact table -->

 <set inverse="true" lazy="false" name="userSet" sort="unsorted" table="USER_CONTACT">

  <key column="USER_ID"/>

  <many-to-many class="com.smallworks.model.Contact" column="CONTACT_ID" unique="false"/>

 </set>

</class>

List contactList = session.createQuery("from Contact").list();

// First, retrieve the user you want.

User user = (User) session.get(User.class, user_id_you_want);

// Second, get the contacts of that given user and add them to a list (optional)

List contacts = new ArrayList();

contacts.addAll(user.getContactSet());

return contacts;

用户.hbm.xml:

public class User {

private Integer userID;

private String userLoginEmail;

private String password;

private Set<Contact> contactSet = new HashSet<Contact>();

.

.

}



public class Contact implements Serializable {

private Integer contactID;

private String givenName;

private String familyName;

private Set<User>  userSet = new HashSet<User>();

.

.

}

<class name="User" table="USERACCOUNT">

  <id column="USER_ID" length="500" name="userID">

    <generator class="increment" />

  </id>

  <property column="USER_LOGIN_EMAIL" generated="never" lazy="false" length="100" name="userLoginEmail" />

  <property column="USER_FIRSTNAME" generated="never" lazy="false" length="100" name="userFirstName" />

  <property column="USER_LASTNAME" generated="never" lazy="false" length="100" name="userLastName" />

  <set name="contactSet" table="USER_CONTACT" inverse="false" lazy="false" fetch="select" cascade="all">

    <key column="USER_ID"/>

    <many-to-many column="CONTACT_ID" class="com.smallworks.model.Contact"/>

  </set>

</class>

<class name="Contact" table="CONTACT">

 <id column="CONTACT_ID" length="500" name="contactID">

 <generator class="increment"/>

 </id>

 <property column="GIVEN_NAME" generated="never" lazy="false" length="100" name="givenName"/>

 <property column="FAMILY_NAME" generated="never" lazy="false" length="100" name="familyName"/>



 <!-- many to many mapping with the User via User_Contact table -->

 <set inverse="true" lazy="false" name="userSet" sort="unsorted" table="USER_CONTACT">

  <key column="USER_ID"/>

  <many-to-many class="com.smallworks.model.Contact" column="CONTACT_ID" unique="false"/>

 </set>

</class>

List contactList = session.createQuery("from Contact").list();

// First, retrieve the user you want.

User user = (User) session.get(User.class, user_id_you_want);

// Second, get the contacts of that given user and add them to a list (optional)

List contacts = new ArrayList();

contacts.addAll(user.getContactSet());

return contacts;

联系人.hbm.xml

public class User {

private Integer userID;

private String userLoginEmail;

private String password;

private Set<Contact> contactSet = new HashSet<Contact>();

.

.

}



public class Contact implements Serializable {

private Integer contactID;

private String givenName;

private String familyName;

private Set<User>  userSet = new HashSet<User>();

.

.

}

<class name="User" table="USERACCOUNT">

  <id column="USER_ID" length="500" name="userID">

    <generator class="increment" />

  </id>

  <property column="USER_LOGIN_EMAIL" generated="never" lazy="false" length="100" name="userLoginEmail" />

  <property column="USER_FIRSTNAME" generated="never" lazy="false" length="100" name="userFirstName" />

  <property column="USER_LASTNAME" generated="never" lazy="false" length="100" name="userLastName" />

  <set name="contactSet" table="USER_CONTACT" inverse="false" lazy="false" fetch="select" cascade="all">

    <key column="USER_ID"/>

    <many-to-many column="CONTACT_ID" class="com.smallworks.model.Contact"/>

  </set>

</class>

<class name="Contact" table="CONTACT">

 <id column="CONTACT_ID" length="500" name="contactID">

 <generator class="increment"/>

 </id>

 <property column="GIVEN_NAME" generated="never" lazy="false" length="100" name="givenName"/>

 <property column="FAMILY_NAME" generated="never" lazy="false" length="100" name="familyName"/>



 <!-- many to many mapping with the User via User_Contact table -->

 <set inverse="true" lazy="false" name="userSet" sort="unsorted" table="USER_CONTACT">

  <key column="USER_ID"/>

  <many-to-many class="com.smallworks.model.Contact" column="CONTACT_ID" unique="false"/>

 </set>

</class>

List contactList = session.createQuery("from Contact").list();

// First, retrieve the user you want.

User user = (User) session.get(User.class, user_id_you_want);

// Second, get the contacts of that given user and add them to a list (optional)

List contacts = new ArrayList();

contacts.addAll(user.getContactSet());

return contacts;

这就是我试图检索数据的方式，我认为这是不正确的。

public class User {

private Integer userID;

private String userLoginEmail;

private String password;

private Set<Contact> contactSet = new HashSet<Contact>();

.

.

}



public class Contact implements Serializable {

private Integer contactID;

private String givenName;

private String familyName;

private Set<User>  userSet = new HashSet<User>();

.

.

}

<class name="User" table="USERACCOUNT">

  <id column="USER_ID" length="500" name="userID">

    <generator class="increment" />

  </id>

  <property column="USER_LOGIN_EMAIL" generated="never" lazy="false" length="100" name="userLoginEmail" />

  <property column="USER_FIRSTNAME" generated="never" lazy="false" length="100" name="userFirstName" />

  <property column="USER_LASTNAME" generated="never" lazy="false" length="100" name="userLastName" />

  <set name="contactSet" table="USER_CONTACT" inverse="false" lazy="false" fetch="select" cascade="all">

    <key column="USER_ID"/>

    <many-to-many column="CONTACT_ID" class="com.smallworks.model.Contact"/>

  </set>

</class>

<class name="Contact" table="CONTACT">

 <id column="CONTACT_ID" length="500" name="contactID">

 <generator class="increment"/>

 </id>

 <property column="GIVEN_NAME" generated="never" lazy="false" length="100" name="givenName"/>

 <property column="FAMILY_NAME" generated="never" lazy="false" length="100" name="familyName"/>



 <!-- many to many mapping with the User via User_Contact table -->

 <set inverse="true" lazy="false" name="userSet" sort="unsorted" table="USER_CONTACT">

  <key column="USER_ID"/>

  <many-to-many class="com.smallworks.model.Contact" column="CONTACT_ID" unique="false"/>

 </set>

</class>

List contactList = session.createQuery("from Contact").list();

// First, retrieve the user you want.

User user = (User) session.get(User.class, user_id_you_want);

// Second, get the contacts of that given user and add them to a list (optional)

List contacts = new ArrayList();

contacts.addAll(user.getContactSet());

return contacts;

如果我能知道如何根据用户获取联系人，那就太好了。

public class User {

private Integer userID;

private String userLoginEmail;

private String password;

private Set<Contact> contactSet = new HashSet<Contact>();

.

.

}



public class Contact implements Serializable {

private Integer contactID;

private String givenName;

private String familyName;

private Set<User>  userSet = new HashSet<User>();

.

.

}

<class name="User" table="USERACCOUNT">

  <id column="USER_ID" length="500" name="userID">

    <generator class="increment" />

  </id>

  <property column="USER_LOGIN_EMAIL" generated="never" lazy="false" length="100" name="userLoginEmail" />

  <property column="USER_FIRSTNAME" generated="never" lazy="false" length="100" name="userFirstName" />

  <property column="USER_LASTNAME" generated="never" lazy="false" length="100" name="userLastName" />

  <set name="contactSet" table="USER_CONTACT" inverse="false" lazy="false" fetch="select" cascade="all">

    <key column="USER_ID"/>

    <many-to-many column="CONTACT_ID" class="com.smallworks.model.Contact"/>

  </set>

</class>

<class name="Contact" table="CONTACT">

 <id column="CONTACT_ID" length="500" name="contactID">

 <generator class="increment"/>

 </id>

 <property column="GIVEN_NAME" generated="never" lazy="false" length="100" name="givenName"/>

 <property column="FAMILY_NAME" generated="never" lazy="false" length="100" name="familyName"/>



 <!-- many to many mapping with the User via User_Contact table -->

 <set inverse="true" lazy="false" name="userSet" sort="unsorted" table="USER_CONTACT">

  <key column="USER_ID"/>

  <many-to-many class="com.smallworks.model.Contact" column="CONTACT_ID" unique="false"/>

 </set>

</class>

List contactList = session.createQuery("from Contact").list();

// First, retrieve the user you want.

User user = (User) session.get(User.class, user_id_you_want);

// Second, get the contacts of that given user and add them to a list (optional)

List contacts = new ArrayList();

contacts.addAll(user.getContactSet());

return contacts;
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