1、MyBatis了解

官方文档：http://mybatis.org/spring-boot-starter/mybatis-spring-boot-autoconfigure/

Maven仓库地址：https://mvnrepository.com/artifact/org.mybatis.spring.boot/mybatis-spring-boot-starter/2.1.3

2、整合流程

数据库提供：

mysql> use springbootDatabase changedmysql> show tables;+----------------------+| Tables_in_springboot |+----------------------+| user                 |+----------------------+1 row in set (0.00 sec)mysql> create table Department(    -> id int primary key,    -> departmentName varchar(20) not null    -> );Query OK, 0 rows affected (0.10 sec)mysql> show tables;+----------------------+| Tables_in_springboot |+----------------------+| department           || user                 |+----------------------+2 rows in set (0.00 sec)mysql> select * from department;+----+----------------+| id | departmentName |+----+----------------+|  1 | JJ             |+----+----------------+1 row in set (0.00 sec)mysql> create table employee(    -> id int primary key,    -> last_name varchar(30) not null,    -> email varchar(50) not null,    -> gender int not null,    -> department int not null,    -> birth Date not null    -> );Query OK, 0 rows affected (0.02 sec)mysql> show tables;+----------------------+| Tables_in_springboot |+----------------------+| department           || employee             || user                 |+----------------------+3 rows in set (0.00 sec)

2.1步骤

1.导入依赖坐标(使用Druid数据库连接池，添加依赖：(参考)


           
               
    
     org.mybatis.spring.boot
                
    
     mybatis-spring-boot-starter
                
    
     2.1.3

2.在application.yml中配置数据库

上一篇已经配置数据源了，不再赘述了：https://blog.csdn.net/qq_45824905/article/details/117327739?spm=1001.2014.3001.5501https://blog.csdn.net/qq_45824905/article/details/117324141---------------------------------------------------------------mapper映射文件配置方式一：在resources目录下，也是开发最常用的。#mybatis 配置mybatis:  #mybatis映射文件存放路径  mapper-locations: classpath:/mapper/*.xml  type-aliases-package: com.austin.pojo  configuration:    #下划线驼峰式的配置    map-underscore-to-camel-case: true#分页配置pagehelper:  helper-dialect: mysql#显示dao层   执行的SQL语句logging:  level:    com:      austin:        mapper: debug

3.测试数据库切换是否成功

在这里插入图片描述

4.创建实体类（Lombok)

@Data@NoArgsConstructor@AllArgsConstructorpublic class Department {
       private Integer id;    private String departmentName;}--------------------------------------------------------------------------------------@Data@AllArgsConstructor@NoArgsConstructorpublic class Employee {
       private Integer id;    private String lastName;    private String email;    private Integer departmentName;    private Integer gender;    private Date birth;    private Department eDepartment; }

5.创建mapper接口和mapper的映射文件

mapper映射文件存放位置：

@Mapper@Repositorypublic interface DepartmentMapper {
       //获取部门全部信息    Department  selectList();    //通过id获取全部部门    Department queryDepartmentById(Integer id);}---------------------------------------------------------------------------------------@Mapperpublic interface EmployeeMapper {
       // 新增员工    int save(Employee employee);    //查询所有的员工    List
   
     selectEmployee();    //通过id查询    Employee selectEmployeeById(Integer id);    //通过id删除    Integer deleteEmployeeById(Integer id);}


   
       
        
        
    
   ---------------------------------------------------------------------
   
   
       
            
             
             
             
             
             
             
                 
                  
              
         
        
        
        
        
    
             insert into employee (last_name, email, gender, dname, birth)        values (#{lastName}, #{email}, #{gender}, #{departmentName}, #{birth})    
        
        
    
             delete        from employee        where id = #{id}

6.maven配置资源过滤问题


           
               
                    
     
      src/main/java
                     
                         
      
       **/*Mapper.xml
                          
      
       **/*.properties
                      
                 
                
                    
     
      src/main/resources
                     
                         
      
       **/*.*

7.编写service测试

@Servicepublic interface DepartmentService {
       Department selectList();    Department queryDepartmentById(Integer id);}@Servicepublic class DepartmentServiceImpl implements DepartmentService {
       @Autowired    private DepartmentMapper departmentMapper;    @Override    public Department selectList() {
           return departmentMapper.selectList();    }    @Override    public Department queryDepartmentById(Integer id) {
           return departmentMapper.queryDepartmentById(id);    }}-------------------------------------------------------------------------------------@Servicepublic interface EmployeeSerive {
       Integer save(Employee employee);    List
   
     selectEmployee();    Employee selectEmployeeById(Integer id);    Integer deleteEmployeeById(Integer id);}@Servicepublic class EmployeeServiceImpl implements EmployeeSerive {
       @Autowired    private EmployeeMapper employeeMapper;    @Override    public Integer save(Employee employee) {
           return employeeMapper.save(employee);    }    @Override    public List
    
      selectEmployee() {
           return employeeMapper.selectEmployee();    }    @Override    public Employee selectEmployeeById(Integer id) {
           return employeeMapper.selectEmployeeById(id);    }    @Override    public Integer deleteEmployeeById(Integer id) {
           return employeeMapper.deleteEmployeeById(id);    }}

8.编写controller层

@Controllerpublic class DepartmentController {
       @Autowired    private DepartmentService departmentService;    @GetMapping("/list")    @ResponseBody    public Department getList() {
           return departmentService.selectList();    }    @GetMapping("/list/{id}")    @ResponseBody    public Department queryDepartmentById(@PathVariable Integer id) {
           return departmentService.queryDepartmentById(id);    }}---------------------------------------------------------------------------------  @Controllerpublic class EmployeeController {
       @Autowired    private EmployeeSerive employeeSerive;    @GetMapping("/add")    @ResponseBody    public Integer save() {
           Employee ep = new Employee();        ep.setLastName("lxx");        ep.setEmail("lxx@qq.com");        ep.setBirth(new Date());        ep.setDepartmentName(1);        ep.setGender(1);        Integer i = employeeSerive.save(ep);        return i;    }    @GetMapping("/ListDe")    @ResponseBody    public List
   
     selectEmployeeList() {
           List
    
      employees = employeeSerive.selectEmployee();        for (Employee employee : employees) {
               System.out.println(employee);        }        return employees;    }    @GetMapping("/listDe/{id}")    @ResponseBody    public Employee selectEmployeeById(@PathVariable("id") Integer id) {
           return employeeSerive.selectEmployeeById(id);    }    @GetMapping("/deleteDe/{id}")    @ResponseBody    public Integer deleteEmployeeById(@PathVariable("id") Integer id) {
           return employeeSerive.deleteEmployeeById(id);    }}