mybatis-plus的特性
首先搭建好springboot项目，引入pom文件
我要评论 <!-- mybatis plus 依赖 -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.1.0</version>
</dependency>
<!-- mybatis 依赖 -->
<dependency>
<groupId>org.mybatis.spring.boot</groupId>
<artifactId>mybatis-spring-boot-starter</artifactId>
<version>2.0.1</version>
</dependency>
<!-- mybatis 根据实体生成数据库表依赖 -->
<dependency>
<groupId>com.gitee.sunchenbin.mybatis.actable</groupId>
<artifactId>mybatis-enhance-actable</artifactId>
<version>1.1.1.RELEASE</version>
</dependency>
连接数据库这一步很关键，这里使用druid连接mysql数据库
<!-- mysql数据库-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!-- druid连接数据库 -->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.10</version>
</dependency>
application-prod.yml数据源配置文件，这里使用com.mysql.cj.jdbc.Driver的druid数据源，你也可以直接写在application.yml配置文件中
spring:
datasource:
url: jdbc:mysql://127.0.0.1:3306/lianxicrud?useUnicode=true&useSSL=false&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
username: root
password: 123456
# 使用druid数据源
type: com.alibaba.druid.pool.DruidDataSource
driver-class-name: com.mysql.cj.jdbc.Driver
server:
port: 8191
新建mapper的空文件
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.psd.domain.User;
import org.apache.ibatis.annotations.Mapper;
@Mapper
public interface UserMapper extends BaseMapper<User>{
}
新建service及impl文件
Service文件继续IService
Impl继承ServiceImpl<UserMapper,User>实现service抽象接口
注ServiceImpl查询是直接this.list()，插入则使用userMapper.insert(user)
修改数据删除数据在单独在文章内容后文补充
import com.baomidou.mybatisplus.extension.service.IService;
import com.psd.domain.User;
import java.util.List;
public interface IUserService extends IService<User>{
/**
* 查询所有
* @return
*/
List<User> listAll();
/**
* id条件查询
* @return
*/
User listOne(Long id);
/***
* 保存
* @param user
* @return
*/
int insert1(User user);
}
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.psd.domain.User;
import com.psd.mapper.UserMapper;
import com.psd.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
import java.util.stream.Collectors;
@Service
public class UserServiceImpl extends ServiceImpl<UserMapper,User> implements IUserService{
@Autowired
private UserMapper userMapper;
//查询所有
@Override
public List<User> listAll() {
List<User> users = this.list();
return users;
}
//条件查询
public User listOne(Long id) {
User user = this.getById(id);
return user;
}
//保存
public int insert1(User user){
return userMapper.insert(user);
}
}
user实体
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;
@TableName("user")
@Data
public class User{
private long id;
private String name;
private int age;
private String email;
//..使用lombok插件省列get set方法
}
控制器应用层类
import com.psd.domain.User;
import com.psd.service.IUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.List;
@RestController
public class UserController {
@Autowired
private IUserService userService;
@GetMapping("/listAll")
public List<User> listAll(){
List<User> users = userService.listAll();
return users;
}
@GetMapping("/listOne")
public User listOne(){
return userService.listOne(1L);
}
//保存
@GetMapping("/save")
public void baocun1(int age,String name,String email){
User user1 = new User();
user1.setAge(age);
user1.setName(name);
user1.setEmail(email);
userService.insert1(user1);
}
}
mybatis-plus修改数据操作
@Test
public void update() {
//修改值
User user = new User();
user.setAge(“20”);
user.setName("李四");
//修改条件意思就是修改值为user.setAge(“20”);user.setName("李四");像setEmail为null的视为不变，然后条件值为id=1
UpdateWrapper<User> userUpdateWrapper = new UpdateWrapper<>();
userUpdateWrapper.eq("id", "1");
boolean update = mapper.update(user, userUpdateWrapper);
System.out.println(update);
}
mybatis-plus删除数据操作
@Test
public void delete() {
QueryWrapper<User> queryWrapper = new QueryWrapper<>();
//条件意思就是删除id=1的并且isNotNull指"id"字段不为空的
queryWrapper
.ge("id", 1)
.isNotNull("id");
int delete = mapper.delete(queryWrapper);
}
直接浏览器请求，那么整个过程就完成了
http://localhost:8191/save?age=18&name=张磊&email=739595798@qq.com
http://www.lhsxpumps.com/_localhost:8191/user/listOne
本文地址：https://blog.csdn.net/gumindong/article/details/107252159
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