Springboot学习笔记7:整合Mybatis
Posted Vincent9847
tags:
篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了Springboot学习笔记7:整合Mybatis相关的知识,希望对你有一定的参考价值。
一、什么是Mybatis?
MyBatis是一款优秀的基于java的持久层框架,它内部封装了jdbc,使开发者只需要关注sql语句本身,而不需要花费精力去处理加载驱动、创建连接、创建statement等繁杂的过程。
二、配置Mybatis
1.导入依赖
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.1</version>
</dependency>
2.配置数据库信息
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/springboot?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8
username: root
password: 123456
type: com.alibaba.druid.pool.DruidDataSource
3.测试连接
@SpringBootTest
class SpringbootDataJdbcApplicationTests {
//DI注入数据源
@Autowired
DataSource dataSource;
@Test
public void contextLoads() throws SQLException {
//看一下默认数据源
System.out.println(dataSource.getClass());
//获得连接
Connection connection = dataSource.getConnection();
System.out.println(connection);
DruidDataSource druidDataSource = (DruidDataSource) dataSource;
//关闭连接
connection.close();
}
}
三、实际开发编写测试
1.编写pojo类 Employee
@Data
@AllArgsConstructor //有参构造方法
@NoArgsConstructor //无参构造方法
public class Employee {
private Integer id;
private String lastName;
private String email;
//1 male, 0 female
private Integer gender;
private Integer department;
private Date birth;
private Department eDepartment; // 冗余设计
}
2.编写 EmployeeDao 接口
@Mapper
@Repository //将类标识为bean
public interface EmployeeMapper {
// 获取所有员工信息
List<Employee> getEmployees();
// 新增一个员工
int save(Employee employee);
// 通过id获得员工信息
Employee get(Integer id);
// 通过id删除员工
int delete(Integer id);
}
3.编写 EmployeeMapper.xml 配置文件
<?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.wwz.dao.EmployeeDao">
<resultMap id="EmployeeMap" type="Employee">
<id property="id" column="eid"/>
<result property="lastName" column="last_name"/>
<result property="email" column="email"/>
<result property="gender" column="gender"/>
<result property="birth" column="birth"/>
<association property="eDepartment" javaType="Department">
<id property="id" column="did"/>
<result property="departmentName" column="dname"/>
</association>
</resultMap>
<select id="getEmployees" resultMap="EmployeeMap">
select e.id as eid,last_name,email,gender,birth,d.id as did,d.department_name as dname
from department d,employee e
where d.id = e.department
</select>
<insert id="save" parameterType="Employee">
insert into employee (last_name,email,gender,department,birth)
values (#{lastName},#{email},#{gender},#{department},#{birth});
</insert>
<select id="get" resultType="Employee">
select * from employee where id = #{id}
</select>
<delete id="delete" parameterType="int">
delete from employee where id = #{id}
</delete>
</mapper>
4.编写 EmployeeController 类
@RestController
public class EmployeeController {
@Autowired
EmployeeMapper employeeMapper;
// 获取所有员工信息
@GetMapping("/getEmployees")
public List<Employee> getEmployees(){
return employeeMapper.getEmployees();
}
@GetMapping("/save")
public int save(){
Employee employee = new Employee();
employee.setLastName("xiaoyi");
employee.setEmail("111@qq.com");
employee.setGender(1);
employee.setDepartment(101);
employee.setBirth(new Date());
return employeeMapper.save(employee);
}
// 通过id获得员工信息
@GetMapping("/get/{id}")
public Employee get(@PathVariable("id") Integer id){
return employeeMapper.get(id);
}
// 通过id删除员工
@GetMapping("/delete/{id}")
public int delete(@PathVariable("id") Integer id){
return employeeMapper.delete(id);
}
}
以上是关于Springboot学习笔记7:整合Mybatis的主要内容,如果未能解决你的问题,请参考以下文章
springboot学习笔记-2 一些常用的配置以及整合mybatis
SpringBoot 学习笔记 -- [spring Boot集成阿里Druid数据源,整合Mybatis搭建一个案例试试]