mybatis之一对一关联

MapperAsso.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="bean.User">
     <!--一对一关联-->
     <select id="selectOneAssoObj" parameterType="int" resultMap="OneAssoObjRM">
         select * from user where id = #{id}
     </select>
     <resultMap type="association.AssoObj" id="OneAssoObjRM">
         <result property="id" column="id"/>
         <result property="name" column="name"/>
         <result property="age" column="age"/>
         <association  property="salary" column="name" select="selectOneSalary"/>
         <!--一对多关联配置备注-->
         <!--<collection property="salarys" ofType="bean.Salary" column="name" select="selectFewSalarys">-->
     </resultMap>

     <select id="selectOneSalary" parameterType="String" resultType="bean.Salary">
         select * from salary where name = #{name}
     </select>

     <!--id：名称； parameterType传入参数类型； resultType：返回数据类型-->
     <select id="selectOneUser" parameterType="int" resultType="bean.User">
         select * from user where id = #{id}
     </select>

     <!--批量查询-->
     <select id="selectAllUser" resultMap="userList">
         select * from user
     </select>
     <resultMap type="first.UserBean" id="userList">
         <result property="id" column="id"/>
         <result property="name" column="name"/>
         <result property="age" column="age"/>
     </resultMap>

 </mapper>

AssoObj.java

 package association;

 import bean.Salary;

 /**
  * 数据封装类
  * user class with Salary object
  * 一对一关联Javabean
  */
 public class AssoObj {
     private int id;
     private String name;
     private String age;
     private Salary salary;

     public AssoObj() {

     }

     public AssoObj(String name, String age) {
         this.name = name;
         this.age = age;
     }

     public AssoObj(int id, String name, String age, Salary salary) {
         this.id = id;
         this.name = name;
         this.age = age;
         this.salary = salary;
     }

     public String getName() {
         return name;
     }

     public void setName(String name) {
         this.name = name;
     }

     public String getAge() {
         return age;
     }

     public void setAge(String age) {
         this.age = age;
     }

     public int getId() {
         return id;
     }

     public void setId(int id) {
         this.id = id;
     }

     public Salary getSalary() {
         return salary;
     }

     public void setSalary(Salary salary) {
         this.salary = salary;
     }

     @Override
     public String toString() {
         return "AssoObj{id：" + id + "; 姓名：" + name +
                 "; 年龄：" + age + "; Salary对象：" + salary + "}";
     }
 }

TestAsso.java

 package association;

 import bean.Salary;
 import bean.User;
 import bean.UserSalary;
 import first.UserBean;
 import org.apache.ibatis.io.Resources;
 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.Ignore;
 import org.junit.Test;
 import zhujie.UserMapperInterface;

 import java.io.IOException;
 import java.io.InputStream;
 import java.util.List;

 /*
 * 一对一关联举例
 *
 * */
 public class TestAsso {
     String resource = "mybatis-config-assosciation.xml";
     SqlSessionFactory sqlSessionFactory = null;
     SqlSession session = null;

     @Before
     public void before() {
 //        System.out.println("Before");
         try {
             InputStream inputStream = Resources.getResourceAsStream(resource);
 //            创建工厂
             sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
 //            创建session对象
             session = sqlSessionFactory.openSession();

         } catch (IOException e) {
             e.printStackTrace();
         }
     }

     @After
     public void close() {
         session.close();
 //        System.out.println("After");
     }

     //    一对一关联测试用例
     @Test
     public void testSelectOneAssoObj() {
         AssoObj assoObj = session.selectOne("bean.User.selectOneAssoObj", 1);
         System.out.println("查询单个AssoObj：" + assoObj);
     }

     @Test
     public void testSelectOneUser() {
         User user = session.selectOne("bean.User.selectOneUser", 1);
         System.out.println("查询单个User：" + user);
     }

     @Test
     public void testSelectAllUser() {
         List<User> listUser = session.selectList("bean.User.selectAllUser");
         System.out.println("记录个数：" + listUser.size());
         System.out.println(listUser);
     }

     @Test
     public void testSelectOneSalary() {
         Salary salary = session.selectOne("bean.User.selectOneSalary", "Tom");
         System.out.println("查询单个Salary：" + salary);
     }

 }

mybatis-config-assosciation.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>
     <!--从外部配置文件导入jdbc信息-->
     <properties resource="jdbc.properties"></properties>

     <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>

     <!--指定映射资源文件-->
     <mappers>
         <mapper resource="association/MapperAsso.xml"/>

     </mappers>
 </configuration>