One-to-one correlation mappings

Hibernate provides two ways to map one-to-one relationships: by foreign key mapping and by primary key mapping.

The following is an example of the employee account and employee Profile table, which describes the two mapping methods:

1. Follow the foreign key map

Step one : Create entity classes Users1 and Resume1

Users1 is created as follows:

Public class Users1 {

Private Integer userid;

Private String username;

Private String Userpass;

Private Resume1 resume1;

.... Slightly

}

RESUME1 is created as follows:

Public class Resume1 {

Private Integer Resid;

Private String Resname;

Private String Rescardno;

Private Users1 users1;

.... Slightly

}

Step two : Configure files Users1.hbm.xml and Resume1.hbm.xml (small configuration)

The Users1.hbm.xml configuration is as follows:

<?xml version= "1.0" encoding= "UTF-8"? ><! DOCTYPE hibernate-mapping public     "-//hibernate/hibernate mapping DTD 3.0//en"    "Http://www.hibernate.org/dtd /hibernate-mapping-3.0.dtd ">
The Resume1.hbm.xml configuration is as follows:
<?xml version= "1.0" encoding= "UTF-8"? ><! DOCTYPE hibernate-mapping public     "-//hibernate/hibernate mapping DTD 3.0//en"    "Http://www.hibernate.org/dtd /hibernate-mapping-3.0.dtd ">
Step three : Test method writing
public void Testadd () {   Session session = Hibernateutil.getsession ();   Transaction tx=session.begintransaction ();   Create a User object   Users1 u1=new Users1 ("Happy", "1");   Create an Archive object   Resume1 r1=new Resume1 ("Primary Archives", "Happy01");   U1.SETRESUME1 (R1);   R1.setusers1 (U1);   Save R1 automatically save U1   Session.save (R1);   Tx.commit ();   System.out.println ("ok===");  }
2. Follow the primary key mapping
Step one : Create entity classes Users2 and Resume2
The USERS2 is created as follows:
 Public class Users2 {
Private Integer userid;
Private String username;
Private String Userpass;
Private Resume2 resume2;
}
The Resume2 is created as follows:
 Public class Resume2 {
Private Integer Resid;
Private String Resname;
Private String Rescardno;
Private Users2 users2;
}
Step two : Configure files Users1.hbm.xml and Resume1.hbm.xml (small configuration)
The Users1.hbm.xml configuration is as follows:
<?xml version= "1.0" encoding= "UTF-8"? ><! DOCTYPE hibernate-mapping public     "-//hibernate/hibernate mapping DTD 3.0//en"    "Http://www.hibernate.org/dtd /hibernate-mapping-3.0.dtd ">
Resume2.hbm.xml Configuration
<?xml version= "1.0" encoding= "UTF-8"? ><! DOCTYPE hibernate-mapping Public "-//hibernate/hibernate mapping DTD 3.0//en"                            "http://www.hibernate.org/dtd/ Hibernate-mapping-3.0.dtd ">
　　
One-to-one correlation mappings