myBatis-Plus快速入门

1.建库建表

2.引入依赖

3.配置

4.编码

5.测试

1.

CREATE TABLE `user` (
  `id` int NOT NULL AUTO_INCREMENT,
  `name` varchar(255) DEFAULT NULL COMMENT '姓名',
  `age` int DEFAULT NULL COMMENT '年龄',
  `email` varchar(50) DEFAULT NULL COMMENT '邮箱',
  `create_time` datetime DEFAULT NULL COMMENT '创建时间',
  PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

2.

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.3.RELEASE</version>
    </parent>
    <dependencies>
       <!--springBoot启动器-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
      <!--springboot test启动器-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
        </dependency>
        <!--lombok简化java代码-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <!--Mybatis-Plus启动器-->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.0</version>
        </dependency>
        <!--MySql jdbc驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
    </dependencies>

3.配置

@SpringBootApplication
@MapperScan("com.example.demo.dao")
public class MpdemoApplication {

    public static void main(String[] args) {

            SpringApplication.run(MpdemoApplication.class, args);
    }

}

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.demo.entity.User;
import org.apache.ibatis.annotations.Mapper;

/**
 * ${todo}
 *
 * @date: 2020/11/11
 * @author: Li Bin
 */
@Mapper
public interface UserMapper extends BaseMapper<User> {
}

package com.example.demo.entity;

import java.time.LocalDateTime;

import lombok.Data;

/**
 * 用户实体类
 *
 * @date: 2020/11/11
 * @author: Li Bin
 */
@Data
public class User {

    private Long id;

    private String name;

    private Integer age;

    private String email;

    private LocalDateTime createTime;

}

代码结构如下：

spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/test
spring.datasource.username=root
spring.datasource.password=root1234

server.port=7001

5.测试

package com.example.demo;

import java.util.List;

import com.example.demo.dao.UserMapper;
import com.example.demo.entity.User;
import org.junit.Assert;
import org.junit.jupiter.api.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;

@SpringBootTest
@RunWith(SpringRunner.class)
public class MpdemoApplicationTests {

    @Autowired
    private UserMapper userMapper;

    @org.junit.Test
    public void select(){
        List<User> users =
            userMapper.selectList(null);

        Assert.assertEquals(3,users.size());
        users.forEach(System.out::println);
    }

}

题外话：

如果不加下面这个依赖：

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-web</artifactId>
</dependency>

则会，不会出现端口号。

Started MpdemoApplication in 2.871 seconds (JVM running for 3.38)

加了以后就变成下面这样的，红色方块会亮起。

Tomcat started on port(s): 7001 (http) with context path ''

Started MpdemoApplication in 2.871 seconds (JVM running for 3.38)