MyBatis-Plus的入坑指南
首先,要使用这玩意,你得需要一个环境,那玩意没有就可以关闭窗口了
- 拥有 Java 开发环境以及相应 IDE
- 熟悉 Spring Boot
- 熟悉 Maven
然后你需要一张测试的表,我直接拿官网的例子过来
DROP TABLE IF EXISTS user;
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)
);
DELETE FROM user;
INSERT INTO user (id, name, age, email) VALUES
(1, 'Jone', 18, '[email protected]'),
(2, 'Jack', 20, '[email protected]'),
(3, 'Tom', 28, '[email protected]'),
(4, 'Sandy', 21, '[email protected]'),
(5, 'Billie', 24, '[email protected]');
数据就和下面这样
然后你需要生成一个测试工程,推荐用idea的自带,也可以去spring.io去生成一个,为了避免有坑,个人建议springboot版本最好是2.2以后的版本
添加依赖
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.5.RELEASE</version>
<relativePath/>
</parent>
引入jar包(官网里面是用的H2,我用的MySQL)
<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>3.3.1.tmp</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.44</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
配置yml
spring:
datasource:
#数据库url
url: jdbc:mysql://localhost:3306/demo?useUnicode=true&characterEncoding=utf8&allowMultiQueries=true&serverTimezone=GMT%2B8&useSSL=false
# 数据库访问账户
username: root
# 数据库访问密码
password: root123
driver-class-name: com.mysql.jdbc.Driver
添加mapper扫描
package com.master.mybatiesplus;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@MapperScan("com.master.mybatiesplus.mapper.*")
public class MybatiesPlusApplication {
public static void main(String[] args) {
SpringApplication.run(MybatiesPlusApplication.class, args);
}
}
编码
实体类
@Data
public class User {
private Long id;
private String name;
private Integer age;
private String email;
}
mapper
public interface UserMapper extends BaseMapper<User> {
}
测试类
@RunWith(SpringRunner.class)
@SpringBootTest
public class SampleTest {
@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);
}
}
运行测试
User(id=1, name=Jone, age=18, email=test1@baomidou.com)
User(id=2, name=Jack, age=20, email=test2@baomidou.com)
User(id=3, name=Tom, age=28, email=test3@baomidou.com)
User(id=4, name=Sandy, age=21, email=test4@baomidou.com)
User(id=5, name=Billie, age=24, email=test5@baomidou.com)
小总结
运行到这说明前面的配置和环境都是没有问题的,接下来进一步操作