Mybatis一对一的关系

逃离我推掉我的手 2022-05-16 15:53 235阅读 0赞

前言：本项目是使用idea进行开发，数据库使用的是Mysql。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3plYWw5cw_size_16_color_FFFFFF_t_70]  
![在这里插入图片描述][20181103083250939.png]  
**1.搭建maven项目,引入mybatis需要的依赖**  
默认没有java、resources、test等文件夹，习惯性建立这几个文件夹，建立文件夹的时候注意标记文件夹的用途（不然编译器无法识别，无法编译代码）  
pom.xml(注意要将实体包下面的xml文件设置可编译)

<?xml version="1.0" encoding="UTF-8"?>
    
    <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
      <modelVersion>4.0.0</modelVersion>
    
      <groupId>Mybatis_02</groupId>
      <artifactId>Mybatis_02</artifactId>
      <version>1.0-SNAPSHOT</version>
      <packaging>war</packaging>
    
      <name>Mybatis_02 Maven Webapp</name>
      
      <url>http://www.example.com</url>
    
      <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <maven.compiler.source>1.7</maven.compiler.source>
        <maven.compiler.target>1.7</maven.compiler.target>
      </properties>
    
      <dependencies>
        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>4.12</version>
          <scope>test</scope>
        </dependency>
        
        <dependency>
          <groupId>org.mybatis</groupId>
          <artifactId>mybatis</artifactId>
          <version>3.4.1</version>
        </dependency>
        
        <dependency>
          <groupId>mysql</groupId>
          <artifactId>mysql-connector-java</artifactId>
          <version>5.1.43</version>
        </dependency>
      </dependencies>
    
      <build>
        
        <resources>
          <resource>
            <directory>src/main/java</directory>
            <includes>
              <include>**/*.xml</include>
            </includes>
          </resource>
        </resources>
        <finalName>Mybatis_02</finalName>
        <pluginManagement>
          <plugins>
            <plugin>
              <artifactId>maven-clean-plugin</artifactId>
              <version>3.0.0</version>
            </plugin>
            
            <plugin>
              <artifactId>maven-resources-plugin</artifactId>
              <version>3.0.2</version>
            </plugin>
            <plugin>
              <artifactId>maven-compiler-plugin</artifactId>
              <version>3.7.0</version>
            </plugin>
            <plugin>
              <artifactId>maven-surefire-plugin</artifactId>
              <version>2.20.1</version>
            </plugin>
            <plugin>
              <artifactId>maven-war-plugin</artifactId>
              <version>3.2.0</version>
            </plugin>
            <plugin>
              <artifactId>maven-install-plugin</artifactId>
              <version>2.5.2</version>
            </plugin>
            <plugin>
              <artifactId>maven-deploy-plugin</artifactId>
              <version>2.8.2</version>
            </plugin>
          </plugins>
        </pluginManagement>
      </build>
    </project>

**2.项目模块图：**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3plYWw5cw_size_16_color_FFFFFF_t_70 1]

**3.在resources目录下新建mybatis的核心配置文件mybatis-config.xml**  
mybatis-config.xml

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
    <configuration>
        
        <typeAliases>
            <package name="com.zs.entity"/>
        </typeAliases>
        <environments default="development">
            <environment id="development">
                <transactionManager type="JDBC" />
                
                <dataSource type="POOLED">
                    <property name="driver" value="com.mysql.jdbc.Driver" />
                    <property name="url" value="jdbc:mysql://localhost:3306/zs?characterEncoding=utf-8" />
                    <property name="username" value="root" />
                    <property name="password" value="1234" />
                </dataSource>
            </environment>
        </environments>
        <mappers>
            <mapper resource="com/zs/entity/Person.xml"></mapper>
        </mappers>
    </configuration>

**4.建立与数据库对应的实体包，包下建立类与对应的xml文件（这里没有使用接口调用方法，是使用xml文件调用方法）**  
Card.java

package com.zs.entity;
    
    /** * @author 小思 * @PackageName:com.zs.entity * @ClassName: Card * @Description: * @date 2018/10/28 18:45 */
    public class Card { 
        private Integer cid;//身份证的Id
        private String cnumber;//身份证的号码
        private Person Person;//
    
        public Card(Integer cid, String cnumber, com.zs.entity.Person person) { 
            this.cid = cid;
            this.cnumber = cnumber;
            Person = person;
        }
    
        public Card(Integer cid, String cnumber) { 
            this.cid = cid;
            this.cnumber = cnumber;
        }
    
        public Card() { 
    
        }
    
        public Integer getCid() { 
            return cid;
        }
    
        public void setCid(Integer cid) { 
            this.cid = cid;
        }
    
        public String getCnumber() { 
            return cnumber;
        }
    
        public void setCnumber(String cnumber) { 
    
    
            this.cnumber = cnumber;
        }
    
        public com.zs.entity.Person getPerson() { 
            return Person;
        }
    
        public void setPerson(com.zs.entity.Person person) { 
            Person = person;
        }
    }

Person.java

package com.zs.entity;
    
    /** * @author 小思 * @PackageName:com.zs.entity * @ClassName: Person * @Description:Person的实体类 * @date 2018/10/28 18:28 */
    public class Person { 
        private Integer pid;//人的id
        private String pname;//人的姓名
        private Card card;//人的身份证
        public Integer getPid() { 
            return pid;
        }
    
        public void setPid(Integer pid) { 
            this.pid = pid;
        }
    
        public String getPname() { 
            return pname;
        }
    
        public void setPname(String pname) { 
            this.pname = pname;
        }
    
        public Card getCard() { 
            return card;
        }
    
        public void setCard(Card card) { 
            this.card = card;
        }
    
        public Person(Integer pid, String pname, Card card) { 
            this.pid = pid;
            this.pname = pname;
            this.card = card;
        }
    
        public Person(Integer pid, String pname) { 
            this.pid = pid;
            this.pname = pname;
        }
    
        public Person() { 
        }
    
    
    
    
    }

Card.xml

Person.xml

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
    <mapper namespace="person">
    
        
        <select id="getAllPerson" resultType="Person">
            select * from person
        </select>
    
    
        
        <select id="getPersonByPid" resultMap="person_card" parameterType="int" >
            select *  from person p,card c where p.cid=c.cid and p.pid=#{pid}
        </select>
    
        
        
        <resultMap id="person_card" type="Person" >
            
            <id column="pid" property="pid"></id>
            
            <result column="pname" property="pname"></result>
            
            <association property="card" javaType="Card" column="cid" >
                <id property="cid" column="cid"></id>
                <result property="cnumber" column="cnumber"></result>
            </association>
        </resultMap>
    
        
        <insert id="addPerson" parameterType="Person">
            insert into person(pname) values(#{pname})
        </insert>
    
    
        
        <update id="updatePerson" parameterType="Person">
            update person set pname=#{pname} where pid=#{pid}
        </update>
    
        
        <update id="updatePerson_card" parameterType="Map">
            update person set pname=#{pname},cid=#{cid} where pid=#{pid}
        </update>
    
    
        
        <delete id="deletePerson" parameterType="int">
            delete from person where pid=#{pid}
        </delete>
    
        
        <delete id="deleteCard" parameterType="int">
            delete from card where pid=#{pid}
        </delete>
    
    
    
    
    
    
    
    </mapper>

**5.在test文件夹下新建com.zs.test文件夹，并且新建单元测试类TestOneToOne.java**  
TestOneToOne.java

package com.zs.test;
    
    import org.apache.ibatis.session.SqlSession;
    import org.apache.ibatis.session.SqlSessionFactory;
    import org.apache.ibatis.session.SqlSessionFactoryBuilder;
    import org.junit.After;
    import org.junit.Before;
    import org.junit.Test;
    
    /** * @author 小思 * @PackageName:com.zs.test * @ClassName: TestOneToOne * @Description:测试一对一关系是否映射成功 * @date 2018/10/28 19:02 */
    public class TestOneToOne { 
        private SqlSessionFactory sessionFactory;
        private SqlSession session;
    
        @Before
        public void before() { 
            sessionFactory = new SqlSessionFactoryBuilder().build(getClass().getClassLoader().getResourceAsStream("mybatis-config.xml"));
            session = sessionFactory.openSession();
        }
    
        @Test
        public void testPerson() { 
    // //通过配置文件Person.xml获取方法
    //
    // //查询所有人的信息（不包括卡）
    // List<Person> ls=session.selectList("person.getAllPerson");
    // for (Person l : ls) { 
    // System.out.println(l.getPname());
    // }
    //
    // //查询单个人和其拥有的卡
    // Person p = session.selectOne("person.getPersonByPid", 1);
    // System.out.println(p.getPname() + "___________" + p.getCard().getCnumber());
    
    // //添加单个的人
    // Person per=new Person();
    // per.setPname("小小");
    // int a=session.insert("person.addPerson",per);
    // System.out.println(a);
    // Person pp=new Person();
    // pp.setPid(1);
    // pp.setPname("大大");
    // Card c=new Card();
    // c.setCid(1);
    // pp.setCard(c);
    // pp.getCard().setCid(2);
    
    // //修改人的信息（不包括卡的信息）
    // Person s=new Person();
    // s.setPid(1);
    // s.setPname("类类");
    // int c=session.update("person.updatePerson",s);
    // System.out.println(c);
    
    // //根据人的id修改人的信息和卡的信息
    // Map<String,String> map=new HashMap<>();
    // map.put("pname","大大");
    // map.put("cid","1");
    // map.put("pid","1");
    // int b=session.update("person.updatePerson_card",map);
    // System.out.println(b);
    
    // //删除人的信息（不包括卡的信息）
    // int d=session.delete("person.deletePerson",1);
    // System.out.println(d);
    
    // //通过人的pid删除人的信息与卡的信息(先删除人后删除卡)
    // int e=session.delete("person.deletePerson",3);
    // int f=session.delete("person.deleteCard",3);
    // System.out.println(e+"___"+f);
    
        }
    
        @Test
        public void testCard(){ 
    // 通过卡的信息找人的信息和人的信息和Person.xml和TesrOneToOne里面的testPerson()测试方法雷同
        }
    
        @After
        public void after() { 
            session.commit();
            session.close();
        }
    }

**6.测试时，取消注释，运行测试类即可。**

如果想节省繁琐的搭建过程，完整项目已上传，能直接运行，请前往[https://download.csdn.net/download/zeal9s/10755856][https_download.csdn.net_download_zeal9s_10755856]下载

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[https_download.csdn.net_download_zeal9s_10755856]: https://download.csdn.net/download/zeal9s/10755856