Mybatis-Plus基础实现最基本的crud

左手的ㄟ右手 2022-02-28 10:44 150阅读 0赞

**一、准备**

**   1、创建数据库表**

CREATE TABLE USER
    (
    	id BIGINT(20) NOT NULL COMMENT '主键ID',
    	NAME VARCHAR(30) NULL DEFAULT NULL COMMENT '姓名',
    	age INT(11) NULL DEFAULT NULL COMMENT '年龄',
    	email VARCHAR(50) NULL DEFAULT NULL COMMENT '邮箱',
    	PRIMARY KEY (id)
    );
    
    
    SELECT * FROM USER
    
    INSERT INTO USER (id, NAME, age, email) VALUES
    (1, 'Jone', 18, 'test1@baomidou.com'),
    (2, 'Jack', 20, 'test2@baomidou.com'),
    (3, 'Tom', 28, 'test3@baomidou.com'),
    (4, 'Sandy', 21, 'test4@baomidou.com'),
    (5, 'Billie', 24, 'test5@baomidou.com');

** 二、初始化一个SpringBoot工程**

**    **    我的项目结构如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNjY3MTQz_size_16_color_FFFFFF_t_70][]

**     2.1 加入相关依赖：**

<parent>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-parent</artifactId>
            <version>2.0.3.RELEASE</version>
            <relativePath/>
        </parent>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter</artifactId>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
            </dependency>
            
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>
            
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.1.0</version>
            </dependency>
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.35</version>
            </dependency>
        </dependencies>

**  2.2 yml文件配置：**

server:
      port: 8888
    spring:
      application:
        name: user-service
      datasource:
        url: jdbc:mysql://127.0.0.1:3306/test
        username: root
        password: 1234
        driver-class-name: com.mysql.jdbc.Driver

**2.3、创建对应实体、mapper接口**

@Data
    @AllArgsConstructor
    @NoArgsConstructor
    public class User {
    
        private Long id;
    
        private  String name;
    
        private  Integer age;
    
        private  String email;
    
    
    
    
    
    
    }

/**
     * 用户的mapper
     */
    public interface UserMapper extends BaseMapper<User> {
    }

**三、创建测试用例完成crud**

@SpringBootApplication
    @MapperScan("com.snym.mapper")
    public class ApplicationStart {
    
    
        public static void main(String[] args) {
            SpringApplication.run(ApplicationStart.class,args);
        }
    }

package com.snym.usertest;
    
    import com.snym.entity.User;
    import com.snym.mapper.UserMapper;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;
    
    import java.util.ArrayList;
    import java.util.List;
    
    /**
     *
     * @author acer
     * @create 2019/3/25
     * @since 1.0.0
     */
    @RunWith(SpringRunner.class)
    @SpringBootTest
    public class SampleTest {
    
        @Autowired
        private UserMapper userMapper;
    
    
        @Test
        public void testSelect(){
            System.out.println("select all");
            List<User> users = userMapper.selectList( null );
            User user = userMapper.selectById( 1 );
            System.out.println(user);
    
            users.forEach(System.out::println);
        }
    
        @Test
        public  void testSave(){
            System.out.println("add one userInfo");
            //新增一条user信息
            int result = userMapper.insert( new User( 7l, "lisi", 22, "kajdakjdka.com" ) );
    
            System.out.println(result);
    
    
        }
    
        @Test
        public  void testUpdate(){
    
            System.out.println("update one userInfo");
    
            User user = new User();
            user.setAge(26);
    
            user.setId(6l);
    
            int i = userMapper.updateById( user );
            System.out.println(i);
    
        }
    
        @Test
        public  void testDelete(){
            System.out.println("delete one userInfo");
            int i = userMapper.deleteById( 6 );
            System.out.println(i);
    
        }
    
        @Test
        public  void testSelectBatchIds(){
            System.out.println("查询（根据ID 批量查询）");
    
            List<Integer> ids=new ArrayList<>();
            ids.add(1);
            ids.add(2);
    
            List<User> users = userMapper.selectBatchIds( ids );
    
            users.forEach( System.out::println);
    
    
        }
    
    
    
    
    
    
    
    
    
    
    
    }

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