整合Mybatis框架

1.Mybatis框架配置

1. 创建springboot项目

   • 勾选web，jdbc ,mysql依赖

2. 在MVNrepository找mybatis的启动依赖：
   

3. 添加依赖：

   <dependency>
               <groupId>org.mybatis.spring.boot</groupId>
               <artifactId>mybatis-spring-boot-starter</artifactId>
               <version>2.2.0</version>
           </dependency> 
   

4. 连接数据库：

   # 应用名称
   spring.application.name=springboot-mybatis
   # 数据库驱动：
   spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
   # 数据源名称
   spring.datasource.name=defaultDataSource
   # 数据库连接地址
   spring.datasource.url=jdbc:mysql://localhost:3306/ssm?useUnicode=true?characterEncoding=utf-8&serverTimezone=UTC
   # 数据库用户名&密码：
   spring.datasource.username=root
   spring.datasource.password=root
   # 应用服务 WEB 访问端口
   server.port=8080
   

2.Mybatis具体实现：

1. 创建实体类，利用lombak实现有参无参构造：

   <!--lombok依赖-->
   <dependency>
       <groupId>org.projectlombok</groupId>
       <artifactId>lombok</artifactId>
   </dependency>
   

   

2. 书写接口

   其中添加注解@Mapper和在spring容器中添加范围注解@MapperScan(“com.qing.mapper”)一个概念

   @MapperScan("com.qing.mapper") //表示可以扫描mapper包下的所有接口
   

3. 在propertise对mybatis进行配置：

   #整合mybatis
   #1.别名的包  2.配置的文件
   mybatis.type-aliases-package= com.qing.pojo 
   mybatis.mapper-locations=classpath:mybatis/mapper/*.xml
   

4.配置mybatis的xml文件：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.qing.mapper.EmployeeMapper">
      <!--查询所有-->
    <select id="queryEmployee" resultType="Employee">
   select * from employee;
    </select>
    <!--查询单个用户-->
    <select id="findEmployeeById" resultType="Employee">
   select * from employee where deptid = #{id};
    </select>
    <!--添加用户-->
    <insert id="addEmployee" parameterType="Employee">
     insert into employee (deptid,username,password) values (#{deptid},#{username},#{password})
    </insert>
    <!--删除用户-->
    <delete id="deleteEmployee" parameterType="int">
   delete * from employee where deptid = #{deptid};
    </delete>
    <!--修改用户-->
    <update id="updateEmployee" parameterType="Employee">
     update employee set username=#{username},password=#{passwoed} where deptid = #{deptid} ;
    </update>

</mapper>

5. service实行代码查询转到controller，我是直接在controller里面做的：

@RestController
public class EmployeeController {
    
    

    @Autowired
    private EmployeeMapper employeeMapper;

    @GetMapping("/employeeList")
    public  List<Employee> queryEmployee(){
    
    
        List<Employee> employees = employeeMapper.queryEmployee();
        for (Employee employee : employees) {
    
    
            System.out.println(employee);
        } b
        
     return employees;
    }
}