快速入门

创建数据库

• 创建一个数据库db1

  create database db1
  

• 创建一个user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)
  );
  

• 插入数据

  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.c	om');
  

编写主体类

• 初始化工程(pom文件)

  <?xml version="1.0" encoding="UTF-8"?>
  <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
      <modelVersion>4.0.0</modelVersion>
      <parent>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-parent</artifactId>
          <version>2.5.2</version>
          <relativePath/> <!-- lookup parent from repository -->
      </parent>
      <groupId>com.example</groupId>
      <artifactId>MyApplication</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <name>MyApplication</name>
      <description>Demo project for Spring Boot</description>
      <properties>
          <java.version>1.8</java.version>
      </properties>
      <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>com.baomidou</groupId>
              <artifactId>mybatis-plus-boot-starter</artifactId>
              <version>3.3.0</version>
          </dependency>
          <dependency>
              <groupId>mysql</groupId>
              <artifactId>mysql-connector-java</artifactId>
              <version>5.1.38</version>
              <scope>runtime</scope>
          </dependency>
          <dependency>
              <groupId>org.projectlombok</groupId>
              <artifactId>lombok</artifactId>
          </dependency>
          <dependency>
              <groupId>junit</groupId>
              <artifactId>junit</artifactId>
              <scope>test</scope>
          </dependency>
      </dependencies>
  
  </project>
  

• application

  spring:
    datasource:
      username: root
      password: 123456
      url: jdbc:mysql://localhost:3306/db1?useUnicode=true&characterEncoding=utf-8&useSSL=true&serverTimezone=UTC
      driver-class-name: com.mysql.jdbc.Driver
  

• User

  package com.blue.bean;
  
  import lombok.Data;
  
  @Data
  public class User {
      private Long id;
      private String name;
      private Integer age;
      private String email;
  }
  

• UserMapper

  package com.blue.mapper;
  
  import com.baomidou.mybatisplus.core.mapper.BaseMapper;
  import com.blue.bean.User;
  
  public interface UserMapper extends BaseMapper<User> {
  
  }
  

• MyApplication

  package com.blue;
  
  import org.mybatis.spring.annotation.MapperScan;
  import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.SpringBootApplication;
  
  @SpringBootApplication
  @MapperScan("com.blue.mapper")
  public class MyApplication {
  
      public static void main(String[] args) {
          SpringApplication.run(MyApplication.class, args);
      }
  }
  

编写测试类

• MyApplicationTests

  package com.blue;
  
  import com.blue.bean.User;
  import com.blue.mapper.UserMapper;
  import org.junit.Assert;
  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.List;
  
  @RunWith(SpringRunner.class)
  @SpringBootTest
  public class MyApplicationTests {
  
      @Autowired
      private UserMapper userMapper;
  
      @Test
      public void testSelect() {
          System.out.println(("----- selectAll method test ------"));
          List<User> userList = userMapper.selectList(null);
          Assert.assertEquals(5, userList.size());
          userList.forEach(System.out::println);
      }
  
  }
  

实验结果

• 控制台输出