目前的大环境下，使用Mybatis作为持久层框架还是占了绝大多数的，下面我们来说一下使用Mybatis的姿势一：零配置注解开发。

1.在pom文件中添加相关依赖坐标

<project xmlns="http://maven.apache.org/POM/4.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>2.1.3.RELEASE</version>
  </parent>
  <groupId>com.neuedu</groupId>
  <artifactId>10-spring-boot-mybatis-01</artifactId>
  <version>0.0.1-SNAPSHOT</version>

  <dependencies>
      <!-- SpringBoot启动器  -->
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-web</artifactId>
      </dependency>
      <!-- MyBatis的依赖坐标  -->
      <dependency>
          <groupId>org.mybatis.spring.boot</groupId>
          <artifactId>mybatis-spring-boot-starter</artifactId>
          <version>1.3.2</version>
      </dependency>
      <!-- MySQL驱动的依赖坐标  -->
      <dependency>
          <groupId>mysql</groupId>
          <artifactId>mysql-connector-java</artifactId>
      </dependency>
  </dependencies>
</project>

2.创建配置文件（application.yml）

spring:
     datasource:
       driver-class-name: com.mysql.cj.jdbc.Driver
       url: jdbc:mysql://localhost:3306/mydb?characterEncoding=UTF-8&serverTimezone=UTC
       username: root
       password: root

3.创建启动类

package com.neuedu;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
/**
* SpringBoot 整合 MyBatis 方式一
* 启动类
* @author 清水三千尺
*
*/
@SpringBootApplication
//这样就不需要在每一个mapper接口上添加@mapper注解
@MapperScan("com.neuedu.mapper")
public class App {
  public static void main(String[] args) throws Exception {
      SpringApplication.run(App.class, args);
  }
}

4.创建数据库表对应实体类

package com.neuedu.po;
import org.springframework.stereotype.Component;

/**
* 数据库表Dept对应的实体类
* @author 清水三千尺
*
*/
@Component
public class Dept {
  private Integer deptno;//部门编号
  private String dname;//部门名称
  private String loc;//部门所在地
  public Integer getDeptno() {
      return deptno;
  }
  public void setDeptno(Integer deptno) {
      this.deptno = deptno;
  }
  public String getDname() {
      return dname;
  }
  public void setDname(String dname) {
      this.dname = dname;
  }
  public String getLoc() {
      return loc;
  }
  public void setLoc(String loc) {
      this.loc = loc;
  }
  
  public Dept() {}
  public Dept(Integer deptno, String dname, String loc) {
      super();
      this.deptno = deptno;
      this.dname = dname;
      this.loc = loc;
  }
  
  @Override
  public String toString() {
      return "Dept [deptno=" + deptno + ", dname=" + dname + ", loc=" + loc + "]";
  }
}

5.创建Mapper接口

package com.neuedu.mapper;

import java.util.List;

import org.apache.ibatis.annotations.Delete;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Select;
import org.apache.ibatis.annotations.Update;

import com.neuedu.po.Dept;

/**
* 部门操作接口
* @author 清水三千尺
*
*/
public interface DeptMapper {
  //查询所有部门信息
  @Select("SELECT * FROM DEPT")
  public List<Dept> selectAllDepts();
  //新增一个部门
  @Insert("INSERT INTO DEPT (DEPTNO,DNAME,LOC) VALUES (#{deptno},#{dname},#{loc})")
  public int insertDept(Dept dept);
  //根据部门编号修改部门信息
  @Update("UPDATE DEPT SET DNAME=#{dname},LOC=#{loc} WHERE DEPTNO =#{deptno}")
  public int updateDeptByDeptno(Dept dept);
  //根据部门编号删除部门信息
  @Delete("DELETE FROM DEPT WHERE DEPTNO =#{deptno}")
  public int deleteDeptByDeptno(Dept dept);
}

6.创建Service接口

package com.neuedu.service;

import java.util.List;

import com.neuedu.po.Dept;

public interface DeptService {
  public List<Dept> selectAllDepts();
  public int insertDept(Dept dept);
  public int updateDeptByDeptno(Dept dept);
  public int deleteDeptByDeptno(Dept dept);
}

7.创建Service接口实现类

package com.neuedu.service.impl;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import com.neuedu.mapper.DeptMapper;
import com.neuedu.po.Dept;
import com.neuedu.service.DeptService;
@Service
public class DeptServiceImpl implements DeptService {
  @Autowired
  private DeptMapper deptMapper;

  @Override
  public List<Dept> selectAllDepts() {
      return deptMapper.selectAllDepts();
  }

  @Override
  public int insertDept(Dept dept) {
      return deptMapper.insertDept(dept);
  }

  @Override
  public int updateDeptByDeptno(Dept dept) {
      return deptMapper.updateDeptByDeptno(dept);
  }

  @Override
  public int deleteDeptByDeptno(Dept dept) {
      return deptMapper.deleteDeptByDeptno(dept);
  }
}

8.创建Controller

package com.neuedu.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import com.neuedu.po.Dept;
import com.neuedu.service.DeptService;

@RestController
@RequestMapping("/dept")
public class DeptController {
  @Autowired
  private DeptService deptService;
  
  @RequestMapping("/findAll")
  public List<Dept> selectAllDepts(){
      return deptService.selectAllDepts();
  }
  
  @RequestMapping("/insertDept")
  public int insertDept(Dept dept) {
      return deptService.insertDept(dept);    
  }
  
  @RequestMapping("/updateDeptByDeptno")
  public int updateDeptByDeptno(Dept dept) {
      return deptService.updateDeptByDeptno(dept);
  }
  
  @RequestMapping("/deleteDeptByDeptno")
  public int deleteDeptByDeptno(Dept dept) {
      return deptService.deleteDeptByDeptno(dept);
  }
}

9.测试

• 查询所有：http://localhost:8080/dept/findAll
  
• 添加部门信息：http://localhost:8080/dept/insertDept?deptno=50&dname=AA&loc=ShenYang
  
• 根据部门编号修改部门信息：http://localhost:8080/dept/updateDeptByDeptno?dname=BB&loc=DongRuan&deptno=50
  
• 根据部门编号删除部门信息：http://localhost:8080/dept/deleteDeptByDeptno?deptno=50