MyBatis 是一款优秀的持久层框架，它支持定制化 SQL、存储过程以及高级映射。MyBatis 避免了几乎所有的 JDBC 代码和手动设置参数以及获取结果集。MyBatis 可以使用简单的 XML 或注解来配置和映射原生信息，将接口和 Java 的 POJOs(Plain Ordinary Java Object,普通的 Java对象)映射成数据库中的记录。
通过注解完成数据操作第一步：引入mysql依赖和mybatis依赖
<dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> </dependency> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>LATEST</version> </dependency>第二步：新建学生表及对应的实体类
CREATE TABLE `student` ( `student_id` int(30) NOT NULL AUTO_INCREMENT, `age` int(1) DEFAULT NULL COMMENT '年龄', `name` varchar(45) DEFAULT NULL COMMENT '姓名', `sex` int(1) DEFAULT NULL COMMENT '性别：1：男，2：女，0：未知', `create_time` datetime DEFAULT NULL COMMENT '创建时间', `status` int(1) DEFAULT NULL COMMENT '状态：1：正常，-1：删除', PRIMARY KEY (`student_id`) ) ENGINE=InnoDB AUTO_INCREMENT=617354 DEFAULT CHARSET=utf8mb4 CHECKSUM=1 DELAY_KEY_WRITE=1 ROW_FORMAT=DYNAMIC COMMENT='学生表' @Data @NoArgsConstructor @AllArgsConstructor public class Student implements Serializable { private static final long serialVersionUID = 6712540741269055064L; private Integer studentId; private Integer age; private String name; private Integer sex; private Date createTime; private Integer status; }第三步：配置数据库连接信息
spring: datasource: driver-class-name: com.mysql.cj.jdbc.Driver url: jdbc:mysql://localhost:3306/simple_fast username: root password: root 增删改查 @Mapper public interface StudentMapper { @Select("select * from student where student_id = #{studentId}") Student findById(@Param("studentId") Integer studentId); @Insert("insert into student(age,name) values(#{age},#{name})") int addStudent(@Param("name") String name,@Param("age") Integer age); @Update("update student set name = #{name} where student_id = #{studentId}") int updateStudent(@Param("studentId") Integer studentId,@Param("name") String name); @Delete("delete from student where student_id = #{studentId}") int deleteStudent(@Param("studentId") Integer studentId); }上面演示的传参方式是通过单个参数传递的，如果想通过Map或实体类传参数，就不需要使用@Param来绑定参数了，将map中的key或者实体类中的属性与sql中的参数值对应上就可以了。
通过XML配置完成数据操作@Mapper和@MapperScan
@Mapper加在数据层接口上，将其注册到ioc容器上，@MapperScan加在启动类上，需要指定扫描的数据层接口包。如下：
@Mapper public interface StudentMapper {} @SpringBootApplication @MapperScan("com.javatrip.mybatis.mapper") public class MybatisApplication { public static void main(String[] args) { SpringApplication.run(MybatisApplication.class, args); } }两个注解的作用一样，在开发中为了方便，通常我们会使用@MapperScan。
指定mapper.xml的位置
mybatis: mapper-locations: classpath:mybatis/*.xml开启数据实体映射驼峰命名
mybatis: configuration: map-underscore-to-camel-case: true编写xml和与之对应的mapper接口
<?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.javatrip.mybatis.mapper.StudentXMapper"> <select resultType="com.javatrip.mybatis.entity.Student"> select * from student where student_id = #{studentId} </select> <insert parameterType="com.javatrip.mybatis.entity.Student"> insert into student(name,age) values(#{name},#{age}) </insert> <update parameterType="com.javatrip.mybatis.entity.Student"> update student set name = #{name} where student_id = #{studentId} </update> <delete parameterType="Integer"> delete from student where student_id = #{studentId} </delete> </mapper> @Mapper public interface StudentXMapper { Student findById(@Param("studentId") Integer studentId); int addStudent(Student student); int updateStudent(@Param("studentId") Integer studentId,@Param("name") String name); int deleteStudent(@Param("studentId") Integer studentId); }编写测试类
@SpringBootTest class MybatisApplicationTests { @Autowired StudentMapper mapper; @Autowired StudentXMapper xMapper; @Test void testMapper() { Student student = mapper.findById(10); mapper.addStudent("Java旅途",19); mapper.deleteStudent(31); mapper.updateStudent(10,"Java旅途"); } @Test void contextLoads() { Student student = xMapper.findById(10); Student studentDo = new Student(); studentDo.setAge(18); studentDo.setName("Java旅途呀"); xMapper.addStudent(studentDo); xMapper.deleteStudent(32); xMapper.updateStudent(31,"Java旅途"); } }