MyBatisPlus-快速入门
一、创建Maven工程
二、pom.xml文件
引入 MyBatis Plus 的依赖,
<?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>2.3.4.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.md</groupId>
<artifactId>01-hello</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>01-hello</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-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--mysql版本-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>5.1.9</scope>
</dependency>
<!--1. 加入依赖-->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.3.1.tmp</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
三、创建实体类
首先数据库中有对应的字段
通过lombok
package com.md.entity;
import lombok.Data;
/**
* @author md
* @Desc
* @date 2020/10/26 15:38
*/
// 2. 使用这个注解直接生成set和get方法
@Data
public class Student {
private Integer id;
private String name;
private Integer age;
}
四、Mapper接口
package com.md.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.md.entity.Student;
/**
* @author md
* @Desc
* @date 2020/10/26 15:46
*/
// 3. 接口继承BaseMapper并指定类型
public interface StudentMapper extends BaseMapper<Student> {
}
五、主配置
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/springboot?serverTimezone=Asia/Shanghai&useUnicode=true&characterEncoding=UTF-8
spring.datasource.username=root
spring.datasource.password=123456
# 专门用于打印日志
mybatis-plus.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
六、启动类
package com.md;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
// 4. mapper扫描
@MapperScan("com.md.mapper")
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
}
七、测试
package com.md;
import com.md.mapper.StudentMapper;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
@SpringBootTest
class ApplicationTests {
@Autowired
private StudentMapper mapper;
// 5. 测试,查询数据
@Test
void contextLoads() {
// 不加条件全部查询,把每个对象迭代出来
mapper.selectList(null).forEach(System.out::println);
}
}
这样就可以把对应的数据查询出来了
作者:山丘!
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