本篇文章为你整理了学习笔记——Mybatis映射文件根标签与子标签(mybatis框架中映射查询结果的标签)的详细内容,包含有mybatisxml映射文件常见标签 mybatis框架中映射查询结果的标签 mybatis映射文件中元素属性 mybatis映射文件名 学习笔记——Mybatis映射文件根标签与子标签,希望能帮助你了解 学习笔记——Mybatis映射文件根标签与子标签。
(1)cache(该命名空间的缓冲配置)
(2)cache-ref(引用其他命名空间的缓存配置)
(3)resultMap(描述如何从数据库结果集中加载对象,是最复杂也是最强大的元素)
注意:resultType解决不了的问题,交给resultMap(一般是多表查询)。
(4)sql(可被其他语句引用的可重用语句块)
(5)insert(映射插入语句)
(6)update(映射更新语句)
(7)delete(映射删除语句)
(8)select(映射查询语句)
3、示例代码
(1)“day02_mybatis.src.main.java.com.hh.mybatis.mapper.EmployeeMapper”中的代码
package com.hh.mybatis.mapper;
import com.hh.mybatis.pojo.Employee;
import java.util.List;
public interface EmployeeMapper {
* 通过id获取员工信息
* @param empId
* @return
public Employee selectEmployee(int empId);
* 添加员工信息
* @param employee
public void insertEmployee(Employee employee);
* 删除员工信息
* @param empId
public void deleteEmployeeById(int empId);
* 修改员工信息
* @param employee
public void updateEmployee(Employee employee);
* 查询所有员工信息
* @return
public List Employee selectAllEmps();
}
(2)映射文件中的代码(day02_mybatis.src.main.resources.mapper下的EmployeeMapper.xml)
?xml version="1.0" encoding="UTF-8" ?
!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"https://mybatis.org/dtd/mybatis-3-mapper.dtd"
mapper namespace="com.hh.mybatis.mapper.EmployeeMapper"
select id="selectEmployee" resultType="employee"
SELECT
last_name,
email,
salary
FROM
tbl_employee
WHERE
id=#{empId}
/select
insert id="insertEmployee"
INSERT INTO
tbl_employee(last_name,email,salary)
VALUES
(#{lastName},#{email},#{salary})
/insert
delete id="deleteEmployeeById"
delete from
tbl_employee
where
id=#{empId}
/delete
update id="updateEmployee"
update
tbl_employee
last_name = #{lastName},
email = #{email},
salary = #{salary}
where
id = #{id}
/update
select id="selectAllEmps" resultType="employee"
SELECT
last_name,
email,
salary
FROM
tbl_employee
/select
/mapper
(3)测试类代码(day02_mybatis.src.test.java.TestMybatis)
import com.hh.mybatis.mapper.EmployeeMapper;
import com.hh.mybatis.pojo.Employee;
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.Test;
import java.io.IOException;
import java.io.InputStream;
import java.util.List;
public class TestMybatis {
@Test
public void TestMybatis(){
try {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//通过sqlSessionFactory获取sqlSession对象
SqlSession sqlSession = sqlSessionFactory.openSession();
//获取EmployeeMapper的代理对象
EmployeeMapper employeeMapper = sqlSession.getMapper(EmployeeMapper.class);
System.out.println("employeeMapper.getClass().getName() = " + employeeMapper.getClass().getName());
Employee employee = employeeMapper.selectEmployee(1);
System.out.println("employee = " + employee);
} catch (IOException e) {
e.printStackTrace();
* 测试添加员工
@Test
public void TestMybatisInsert(){
try {
String resource = "mybatis-config.xml";
InputStream inputStream = Resources.getResourceAsStream(resource);
SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
//通过sqlSessionFactory获取sqlSession对象
SqlSession sqlSession = sqlSessionFactory.openSession();
//获取EmployeeMapper的代理对象
EmployeeMapper employeeMapper = sqlSession.getMapper(EmployeeMapper.class);
// Employee wangwu = new Employee(null,"wangwu","zs@163.com",50.0);
//测试添加员工信息
// employeeMapper.insertEmployee(wangwu);
//测试删除员工信息
// employeeMapper.deleteEmployeeById(2);
// Employee wangwu = new Employee(1,"zhangsan1","zs1@163.com",102.0);
// employeeMapper.updateEmployee(wangwu);
//查询所有员工信息
List Employee employees = employeeMapper.selectAllEmps();
for (Employee employee : employees) {
System.out.println("employee = " + employee);
//提交事务
sqlSession.commit();
} catch (IOException e) {
e.printStackTrace();
}
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