Mybatis-plus插件的学习与使用

本文是基于Windows 10系统环境，利用mybatis-plus实现数据库表的CRUD

• Windows 10
• IntelliJ

一、构建过程（简单入门）

(1) 打开IntelliJ，创建一个新项目

(2) 选择“maven”工程，然后点击“next”

(3) 填写公司ID等信息，然后点击“next”

(4) 填写项目名称等信息，然后点击“finish”

(5) 点击“pom.xml”文件，然后填写各种依赖的坐标

<?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 http://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>2.1.4.RELEASE</version>
    </parent>

    <groupId>com.inspur.intellid</groupId>
    <artifactId>mybatis-plus-demo</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-starter-logging</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
        </dependency>
        <!-- mybatis-plus的spring-boot支持 -->
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.1.1</version>
        </dependency>
        <!-- mysql的驱动支持 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.47</version>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
</project>

(6) 创建一个User类，然后生成相应的属性和方法

package com.inspur.intellid.mybatisplus.pojo;

import com.baomidou.mybatisplus.annotation.TableName;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@NoArgsConstructor
@AllArgsConstructor
@TableName(\"user\")
public class User {
    private String id;
    private String username;
    private String nickname;
    private String type;
    private String password;

}

(7) 创建一个UserMapper类

package com.inspur.intellid.mybatisplus.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.inspur.intellid.mybatisplus.pojo.User;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface UserMapper extends BaseMapper<User> {
}

(8) 创建一个MybatisPlusApplication启动类

package com.inspur.intellid.mybatisplus;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@MapperScan(\"com.inspur.intellid.mybatisplus.mapper\")
@SpringBootApplication
public class MybatisPlusApplication {
    public static void main(String args) {
        SpringApplication.run(MybatisPlusApplication.class, args);
    }
}

(9) 创建一个主配置文件Application.properties

(10) 创建一个UserMapper类

package com.inspur.intellid.mybatisplus.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.inspur.intellid.mybatisplus.pojo.User;
import org.apache.ibatis.annotations.Mapper;

@Mapper
public interface UserMapper extends BaseMapper<User> {
}

(11) 写一个测试类，测试CRUD结果

package com.inspur.intellid.mybatisplus.mapper;

import com.inspur.intellid.mybatisplus.pojo.User;
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.SpringJUnit4ClassRunner;

import java.util.List;

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
public class UserMapperTest {
    @Autowired
    private UserMapper userMapper;

    @Test
    public void testSelect(){
        List<User> users = this.userMapper.selectList(null);
        for(User user : users){
            System.out.println(user);
        }
    }
}

结果如图

原文：https://blog.csdn.net/qq_32599479/article/details/103923433