一对一关系数据库表 java类描述

• Z时代
• 2024-01-10
• 分类：综合

一对一关系中 从表的主键是 主表的外键

sql语句

1 create table person(
2     id int primary key,
3     name varchar(100)
4 );
5 create table idcard(
6     id int primary key,
7     num varchar(20),
8     constraint person_id_fk foreign key(id) references person(id)
9 );

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domain

Person.java

 1 package cn.itcast.domain;
 2 
 3 import java.io.Serializable;
 4 /*
 5 create table person(
 6     id int primary key,
 7     name varchar(100)
 8 );
 9 create table idcard(
10     id int primary key,
11     num varchar(20),
12     constraint person_id_fk foreign key(id) references person(id)
13 );
14  */
15 public class Person implements Serializable {
16     private Integer id;
17     private String name;
18     private IdCard idcard;
19     public Integer getId() {
20         return id;
21     }
22     public void setId(Integer id) {
23         this.id = id;
24     }
25     public String getName() {
26         return name;
27     }
28     public void setName(String name) {
29         this.name = name;
30     }
31     public IdCard getIdcard() {
32         return idcard;
33     }
34     public void setIdcard(IdCard idcard) {
35         this.idcard = idcard;
36     }
37     
38 }

View Code

IdCard.java

 1 package cn.itcast.domain;
 2 
 3 import java.io.Serializable;
 4 
 5 public class IdCard implements Serializable {
 6     private Integer id;
 7     private String num;
 8     private Person person;
 9     public Integer getId() {
10         return id;
11     }
12     public void setId(Integer id) {
13         this.id = id;
14     }
15     public String getNum() {
16         return num;
17     }
18     public void setNum(String num) {
19         this.num = num;
20     }
21     public Person getPerson() {
22         return person;
23     }
24     public void setPerson(Person person) {
25         this.person = person;
26     }
27     
28 }

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daoImpl.java

 1 package cn.itcast.dao.impl;
 2 
 3 import java.sql.SQLException;
 4 
 5 import org.apache.commons.dbutils.QueryRunner;
 6 import org.apache.commons.dbutils.handlers.BeanHandler;
 7 
 8 import cn.itcast.domain.IdCard;
 9 import cn.itcast.domain.Person;
10 import cn.itcast.util.DBCPUtil;
11 
12 public class PersonDaoImpl {
13     private QueryRunner qr = new QueryRunner(DBCPUtil.getDataSource());
14     public void addPerson(Person p) throws SQLException{
15         //保存人的基本信息
16         qr.update("insert into person (id,name) values(?,?)", p.getId(),p.getName());
17         //如果有身份证，保存身份证的基本信息
18         IdCard card = p.getIdcard();
19         if(card!=null){
20             qr.update("insert into idcard (id,num) values(?,?)", p.getId(),card.getNum());
21         }
22     }
23     //要不要查IdCard的内容。都要求查，因为Idcard是少的一方的
24     public Person findPerson(Integer id) throws SQLException{
25         Person p = qr.query("select * from person where id=?", new BeanHandler<Person>(Person.class), id);
26         if(p!=null){
27             IdCard idcard = qr.query("select * from idcard where id=?", new BeanHandler<IdCard>(IdCard.class), id);
28             p.setIdcard(idcard);
29         }
30         return p;
31     }
32 }

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test测试

 1 package cn.itcast.test;
 2 
 3 import static org.junit.Assert.fail;
 4 
 5 import java.sql.SQLException;
 6 
 7 import org.junit.Test;
 8 
 9 import cn.itcast.dao.impl.PersonDaoImpl;
10 import cn.itcast.domain.IdCard;
11 import cn.itcast.domain.Person;
12 
13 public class PersonDaoImplTest {
14     private PersonDaoImpl dao = new PersonDaoImpl();
15     @Test
16     public void testAddPerson() throws SQLException {
17         Person p = new Person();
18         p.setId(1);
19         p.setName("zql");
20         
21         IdCard idcard = new IdCard();
22         idcard.setNum("110");
23         
24         p.setIdcard(idcard);
25         dao.addPerson(p);
26     }
27 
28     @Test
29     public void testFindPerson() throws SQLException {
30         Person p = dao.findPerson(1);
31         System.out.println(p.getName());
32         IdCard idcard = p.getIdcard();
33         System.out.println(idcard.getNum());
34     }
35 
36 }

View Code

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