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类型、接口和 Java 的 POJO（Plain Old Java Objects，普通老式 Java 对象）为数据库中的记录。
建库建表- 建库
CREATE DATABASE test;
- 建表
CREATE TABLE `users` ( `id` bigint(20) NOT NULL AUTO_INCREMENT COMMENT '主键id', `userName` varchar(32) DEFAULT NULL COMMENT '用户名', `passWord` varchar(32) DEFAULT NULL COMMENT '密码', `user_sex` varchar(32) DEFAULT NULL, `nick_name` varchar(32) DEFAULT NULL, PRIMARY KEY (`id`) ) ENGINE=InnoDB AUTO_INCREMENT=32 DEFAULT CHARSET=utf8;pom.xml文件
添加MyBatis依赖和MySQL依赖.
实体类4.0.0 org.springframework.boot spring-boot-starter-parent 2.1.7.RELEASE com.huzh springboot-mybatis 1.0-SNAPSHOT springboot-mybatis springboot-mybatis 1.8 2.1.0 org.springframework.boot spring-boot-starter-jdbc org.springframework.boot spring-boot-starter-web org.mybatis.spring.boot mybatis-spring-boot-starter ${mybatis.version} mysql mysql-connector-java runtime org.springframework.boot spring-boot-devtools runtime true org.springframework.boot spring-boot-starter-test test org.springframework.boot spring-boot-maven-plugin
- 实体类
public class User implements Serializable {
private static final long serialVersionUID = 1L;
private Long id;
private String userName;
private String passWord;
private UserSexEnum userSex;
private String nickName;
public User() {
super();
}
public User(String userName, String passWord, UserSexEnum userSex) {
super();
this.passWord = passWord;
this.userName = userName;
this.userSex = userSex;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getPassWord() {
return passWord;
}
public void setPassWord(String passWord) {
this.passWord = passWord;
}
public UserSexEnum getUserSex() {
return userSex;
}
public void setUserSex(UserSexEnum userSex) {
this.userSex = userSex;
}
public String getNickName() {
return nickName;
}
public void setNickName(String nickName) {
this.nickName = nickName;
}
@Override
public String toString() {
// TODO Auto-generated method stub
return "userName " + this.userName + ", pasword " + this.passWord + "sex " + userSex.name();
}
}
- 枚举类
public enum UserSexEnum {
MAN, WOMAN
}
两种整合模式
注解模式
配置mybatis和数据库
spring:
datasource:
driver-class-name: com.mysql.jdbc.Driver
username: root
password: 123456
url: jdbc:mysql://localhost:3306/test?serverTimezone=GMT
mybatis:
#这个配置用来指定bean在哪个包里，避免存在同名class时找不到bean
type-aliases-package: com.huzh.springbootmybatisannotation.model
编写 Mapper 层
public interface UserMapper {
@Select("SELECT * FROM users")
@Results({
@Result(property = "userSex", column = "user_sex", javaType = UserSexEnum.class),
@Result(property = "nickName", column = "nick_name")
})
List getAll();
@Select("SELECT * FROM users WHERe id = #{id}")
@Results({
@Result(property = "userSex", column = "user_sex", javaType = UserSexEnum.class),
@Result(property = "nickName", column = "nick_name")
})
User getOne(Long id);
@Insert("INSERT INTO users(userName,passWord,user_sex) VALUES(#{userName}, #{passWord}, #{userSex})")
void insert(User user);
@Update("UPDATE users SET userName=#{userName},nick_name=#{nickName} WHERe id =#{id}")
void update(User user);
@Delete("DELETE FROM users WHERe id =#{id}")
void delete(Long id);
}
创建controller
@RestController
public class UserController {
@Autowired
private UserMapper userMapper;
@RequestMapping("/getUsers")
public List getUsers() {
List users=userMapper.getAll();
return users;
}
@RequestMapping("/getUser")
public User getUser(Long id) {
User user=userMapper.getOne(id);
return user;
}
@RequestMapping("/add")
public void save(User user) {
userMapper.insert(user);
}
@RequestMapping(value="update")
public void update(User user) {
userMapper.update(user);
}
@RequestMapping(value="/delete/{id}")
public void delete(@PathVariable("id") Long id) {
userMapper.delete(id);
}
}
xml模式
配置mybatis和数据库
- 指定了 Mybatis 基础配置文件和实体类映射文件的地址。
spring:
datasource:
driver-class-name: com.mysql.jdbc.Driver
username: root
password: 123456
url: jdbc:mysql://localhost:3306/test?serverTimezone=GMT
mybatis:
#这个配置用来指定bean在哪个包里，避免存在同名class时找不到bean
type-aliases-package: com.huzh.springbootmybatisxml.model
##检查 mybatis 配置是否存在，一般命名为 mybatis-config.xml
check-config-location: true
##配置文件位置
config-location: classpath:mybatis/mybatis-config.xml
## dao xml 文件地址
mapper-locations: classpath:mapper/*Mapper.xml
- mybatis-config.xml 配置
添加 User 的映射文件
编写 Mapper 层id, userName, passWord, user_sex, nick_name
public interface UserMapper {
List getAll();
User getOne(Long id);
void insert(User user);
void update(User user);
void delete(Long id);
}
创建Controller
@RestController
public class UserController {
@Autowired
private UserMapper userMapper;
@RequestMapping("/getUsers")
public List getUsers() {
List users = userMapper.getAll();
return users;
}
@RequestMapping("/getUser")
public User getUser(Long id) {
User user = userMapper.getOne(id);
return user;
}
@RequestMapping("/add")
public void save(User user) {
userMapper.insert(user);
}
@RequestMapping(value = "update")
public void update(User user) {
userMapper.update(user);
}
@RequestMapping(value = "/delete/{id}")
public void delete(@PathVariable("id") Long id) {
userMapper.delete(id);
}
}
启动类
添加对 mapper 包扫描@MapperScan，可以直接在 Mapper 类上面添加注解@Mapper，建议使用下面那种，不然每个 mapper 要加个注解。
@MapperScan("com.huzh.springbootmybatisxml.mapper")
@SpringBootApplication
public class SpringbootMybatisXmlApplication {
public static void main(String[] args) {
SpringApplication.run(SpringbootMybatisXmlApplication.class, args);
}
}
