mybatis映射文件_select_resultMap

实体类：

Employee.java类：

package com.hand.mybatis.bean;

public class Employee {

   private Integer eId;
   private String eName;
   private Integer gender;
   private String email;
   private Department dept;

   public Employee() {
       super();
   }

   public Employee(Integer eId,String eName, Integer gender, String email) {
       super();
       this.eId=eId;
       this.eName = eName;
       this.gender = gender;
       this.email = email;
   }

   public Integer geteId() {
       return eId;
   }
   public void seteId(Integer eId) {
       this.eId = eId;
   }

   public String getEName() {
       return eName;
   }
   public void setEname(String ename) {
       this.eName = ename;
   }
   public Integer getGender() {
       return gender;
   }
   public void setGender(Integer gender) {
       this.gender = gender;
   }
   public String getEmail() {
       return email;
   }
   public void setEmail(String email) {
       this.email = email;
   }

   public Department getDept() {
       return dept;

}

   public void setDept(Department dept) {
       this.dept = dept;
   }
   @Override
   public String toString() {
       return "Employee [eId=" + eId + ", ename=" + eName + ", gender=" + gender + ", email=" + email + "]";

}

Department实体类：

package com.hand.mybatis.bean;
import java.util.List;
public class Department {
   private Integer id;
   private String departName;
    private List<Employee> empList;

   public Integer getId() {
       return id;
   }
   public void setId(Integer id) {
       this.id = id;
   }
   public String getDepartName() {
       return departName;
   }
   public void setDepartName(String departName) {
       this.departName = departName;
   }

   public List<Employee> getEmpList() {
       return empList;
   }
   public void setEmpList(List<Employee> empList) {
       this.empList = empList;
   }
   @Override
   public String toString() {
       return "Department [;
   }
}

EmployeeMapperPlus.xml 映射文件

<?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="com.hand.mybatis.dao.EmployeeMapperPlus">


<resultMap type="com.hand.mybatis.bean.Employee" > 1.简单的 javaBean映射

mapper接口一

<select >/association>
</resultMap>

（1）关联查询级联属性封装结果集

（2）使用association定义单个对象的封装规则

mapper接口二
<select >将ename这一列的值赋值给emai

<id column="eid" property="eId"/>
             <result column="ename" property="eName"/>
             <result column="gender" property="gender"/>
             <result column="eName" property="email"/>
        </case>
    </discriminator>
   </resultMap>

   接口四
   <select >
      select * from emp where eid=#{eid}
   </select>

接口四结果：

（1） Employee emp= mapper.getEmpByIdDis(101);

若员工101的gender=0(女生)，

则结果为：有部门信息

Employee [eId=101, ename=张三, gender=0, email=2714763867@qq.com]
Department [id=1, departName=销售部]

（2）Employee emp= mapper.getEmpByIdDis(103);

若员工103的gender=1(男生)，

则结果为：无部门信息，并且email的为ename的值杨张

Employee [eId=103, ename=杨张, gender=1, email=杨张]
null

</mapper>

代码：https://github.com/shuaishuaihand/mybatis.git