有两种方式：
@注解版
新增依赖：
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.1.2</version>
</dependency>
经典全局配置文件：
spring:
datasource:
driver-class-name: com.mysql.cj.jdbc.Driver
url: jdbc:mysql://localhost:3306/springboot?useUnicode=true&characterEncoding=utf8&serverTimezone=UTC
username: root
password: 123456
准备实体类：
public class Department {
private Integer id;
private String departmentName;
//省略构造器，get/set方法,省略toString方法
}
mapper层接口： 举例如下
//指定这是一个操作数据库的mapper
/*可以使用mapper的批量扫描注解 ,写在启动类上*/
//@Mapper
public interface DepartmentMapper {
@Select("select * from department where id=#{id}")
public Department getDeptById(Integer id);
@Delete("delete from department where id=#{id}")
public int deleteDeptById(Integer id);
@Options(useGeneratedKeys = true,keyProperty = "id") //自动生成主键 并且指定对应属性
@Insert("insert into department(department_name) values(#{departmentName})")
public int insertDept(Department department);
@Update("update department set department_name=#{departmentName} where id=#{id}")
public int updateDept(Department department);
}
controller层：
@RestController
public class DeptController {
@Autowired
private DepartmentMapper departmentMapper;
@GetMapping("/dept/{id}")
public Department getDepartment(@PathVariable("id") Integer id) {
return departmentMapper.getDeptById(id);
}
@GetMapping("/dept")
public Department insertDept(Department department) {
departmentMapper.insertDept(department);
return department;
}
}
数据库的命名：
Java实体类的命名：
由于数据库的命名规范和Java不统一，所有需要始终驼峰命名配置
@Configuration
public class MybatisConfig {
@Bean
public ConfigurationCustomizer configurationCustomizer(){
return new ConfigurationCustomizer() {
@Override
public void customize(org.apache.ibatis.session.Configuration configuration) {
/*配置使用驼峰命名规则*/
configuration.setMapUnderscoreToCamelCase(true);
}
};
}
}
浏览器访问：
当mapper层接口较多时，可是使用@MapperScan注解加在住类上：
使用MapperScan批量扫描所有的Mapper接口；
@MapperScan(value = "com.xxx.xxx.mapper")
@SpringBootApplication
public class SpringBoot06DataMybatisApplication {
public static void main(String[] args) {
SpringApplication.run(SpringBoot06DataMybatisApplication.class, args);
}
}
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配置文件版:
文件结构 举例如下：
Mybatis的全局配置文件
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
<!--设置驼峰命名映射-->
<settings>
<setting name= "mapUnderscoreToCamelCase" value="true"/>
</settings>
</configuration>
xxxMapper.xml文件的配置：(很常见的那种)
<?xm1 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.atguigu.springboot.mapper.EmployeeMapper">
<select id="getEmpById" resultType="com.atguigu.springboot.bean.Employee">
SELECT * FROM employee WHERE id=#{id}
</select>
</mapper>
为了使这两个文件生效，在application.yml中设置：
mybatis:
config-location: classpath:mybatis/mybatis-config.xml #指定全局配置文件的位置
mapper-locations: classpath:mybatis/mapper/*.xml #指定sql映射文件的位置
之后就可以写controller层的方法了
至此完成了一个Mybatis的配置文件版
更多使用参照