Mybatis-plus插件的学习与使用

浅浅的花香味﹌ 2021-09-21 01:58 484阅读 0赞

# 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**

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## 一、构建过程（简单入门） ##

### (1) 打开IntelliJ，创建一个新项目 ###

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### (2) 选择“maven”工程，然后点击“next” ###

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### (3) 填写公司ID等信息，然后点击“next” ###

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### (4) 填写项目名称等信息，然后点击“finish” ###

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### (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>
            
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.1.1</version>
            </dependency>
            
            <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>

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMyNTk5NDc5_size_16_color_FFFFFF_t_70 4]  
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### (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;
    
    }

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### (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> { 
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMyNTk5NDc5_size_16_color_FFFFFF_t_70 9]

### (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);
        }
    }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMyNTk5NDc5_size_16_color_FFFFFF_t_70 10]

### (9) 创建一个主配置文件Application.properties ###

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spring.application.name=mybatis-plus-demo
    
    spring.datasource.driver-class-name=com.mysql.jdbc.Driver
    spring.datasource.url=jdbc:mysql://localhost:3306/zs200
    spring.datasource.username=root
    spring.datasource.password=123456

### (10) 创建一个UserMapper类 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMyNTk5NDc5_size_16_color_FFFFFF_t_70 12]

### (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  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMyNTk5NDc5_size_16_color_FFFFFF_t_70 13]

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[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzMyNTk5NDc5_size_16_color_FFFFFF_t_70 1]: /images/20210920/d3657735884c44ad96d1fd1ee421b3a0.png
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