详解springboot+mybatis-plue实现内置的CRUD使用详情

<!-- 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>

<!-- 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>

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 

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>{
}

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);

 }

}

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

}

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);
 }
}

@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);
 }

@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);
 }