mybatis一对一关联

一.导入资源

<dependencies><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.3.0</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.20</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency></dependencies>

二.创建数据库表

CREATE DATABASE /*!32312 IF NOT EXISTS*/`mybatis` /*!40100 DEFAULT CHARACTER SET latin1 */;USE `mybatis`;create table t_wife( id int primary key auto_increment, wife_name varchar(20), fk_husband_id int);create table t_husband(id int primary key auto_increment,husband_name varchar(20));insert into t_husband values (null,'hello');insert into t_wife values(null,'kitty',1)

三.创建基本对象

public class Wife implements Serializable{        private static final long serialVersionUID = 1L;    private Integer id;    private String name;    private Husband husband;    public Wife() {        super();    }    public Wife(Integer id, String name, Husband husband) {        super();        this.id = id;        this.name = name;        this.husband = husband;    }    public Integer getId() {        return id;    }    public void setId(Integer id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public Husband getHusband() {        return husband;    }public void setHusband(Husband husband) {        this.husband = husband;    }    @Override    public String toString() {        return "Wife [id=" + id + ", name=" + name + ", husband=" + husband                + "]";    }}public class Husband implements Serializable {private static final long serialVersionUID = 1L;private Integer id;private String name;private Wife wife;public Husband() {super();}public Husband(int id, String name, Wife wife) {super();this.id = id;this.name = name;this.wife = wife;}public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Wife getWife() {return wife;}public void setWife(Wife wife) {this.wife = wife;}@Overridepublic String toString() {return "Husband [id=" + id + ", name=" + name + ", wife=" + wife + "]";}}

四.创建接口以及映射文件

public interface HusbandDao {public Husband selectHusbandById(int id) throws Exception;public Husband selectHusbandAndWife(int id) throws Exception;}public interface WifeDao {public Husband selectWifeByHusbandId(int id) throws Exception;}<mapper namespace="com.dao.HusbandDao"><resultMap type="Husband" id="husbandAndWife"><id property="id" column="id" javaType="java.lang.Integer" /><result property="name" column="husband_name" javaType="java.lang.String" /><association property="wife" column="id" javaType="Wife"select="com.dao.WifeDao.selectWifeByHusbandId"></association></resultMap><select id="selectHusbandById" resultType="Husband">select * from t_husband where id=#{id}</select><select id="selectHusbandAndWife" resultMap="husbandAndWife">select * from t_husband where id=#{id}</select></mapper><mapper namespace="com.dao.WifeDao"><select id="selectWifeByHusbandId" resultType="Wife">selectid,wife_name as name fromt_wife where fk_husband_id = #{id}</select></mapper>

五.创建配置文件mybatis-config.xml以及数据库配置文件config.properties

<configuration><properties resource="config.properties"></properties><typeAliases><typeAlias alias="Wife" type="com.domain.Wife" /><typeAlias alias="Husband" type="com.domain.Husband" /></typeAliases><environments default="development"><environment id="development"><transactionManager type="JDBC" /><dataSource type="POOLED"><property name="driver" value="${driver}" /><property name="url" value="${url}" /><property name="username" value="${username}" /><property name="password" value="${password}" /></dataSource></environment></environments><mappers><mapper resource="mapper/WifeMapper.xml" /><mapper resource="mapper/HusbandMapper.xml" /></mappers></configuration>driver=com.mysql.jdbc.Driverurl=jdbc:mysql:///mybatisusername=rootpassword=root

六.编写单元测试

public class HusbandDaoTest {SqlSession session = null;HusbandDao husbandDao = null;@Beforepublic void setUp() throws Exception {String resource = "mybatis-config.xml";InputStream inputStream = Resources.getResourceAsStream(resource);SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);session = sqlSessionFactory.openSession();husbandDao = (HusbandDao) session.getMapper(HusbandDao.class);}@Afterpublic void tearDown() throws Exception {session.commit();session.close();}@Testpublic void testSelectHusbandAndWife() throws Exception {Husband husband = husbandDao.selectHusbandAndWife(1);System.out.println(husband);}}

源码链接：https://github.com/wangjianyangchn/myBatis/tree/master/AssociationOnetoOne


参考文档：http://www.mybatis.org/mybatis-3/zh/index.html