mybatis-plus 入门程序

谁借莪１个温暖的怀抱￠ 2024-04-19 07:17 0阅读 0赞

### 项目目录 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDU4ODQ5NQ_size_16_color_FFFFFF_t_70]

### 1、添加坐标 ###

<?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>2.1.0.RELEASE</version>
        </parent>
    
        <groupId>com.puls</groupId>
        <artifactId>mybatis-plus</artifactId>
        <version>1.0-SNAPSHOT</version>
    
        <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>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>
    
            <dependency>
                <groupId>com.baomidou</groupId>
                <artifactId>mybatis-plus-boot-starter</artifactId>
                <version>3.0.5</version>
            </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.47</version>
            </dependency>
        </dependencies>
        <build>
            <plugins>
                <plugin>
                    <groupId>org.springframework.boot</groupId>
                    <artifactId>spring-boot-maven-plugin</artifactId>
                </plugin>
            </plugins>
        </build>
    </project>

### 2、编写配置文件 ###

数据库配置信息

spring.application.name=demo
    spring.datasource.driver-class-name=com.mysql.jdbc.Driver
    spring.datasource.url=jdbc:mysql://localhost:3306/heiheihei?useUnicode=true&characterEncoding=utf-8&serverTimezone=CTT
    spring.datasource.username=root
    spring.datasource.password=root

### 3、编写启动类 ###

这里采用的是springboot整合mybatis-plus

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

### 4、编写实体类 ###

这里要对应表中的表名和字段

package com.puls.enity;
    public class Account { 
    
        private long id;
        private String name;
        private double money;
    	省略get、set、toString方法
    }

### 5、表 ###

![在这里插入图片描述][20190915110603732.png]

### 6、编写mapper映射接口 ###

BaseMapper<T>是mybatis-plus提供的一个类，这个类封装了操作单表的基本方法。

package com.puls.mapper;
    
    import com.baomidou.mybatisplus.core.mapper.BaseMapper;
    import com.puls.enity.Account;
    public interface AccountMapper extends BaseMapper<Account> { 
    }

### 7、测试类 ###

private AccountMapper accountMapper;这句话可能在idea中会报错，但是其实是没错的，mybatis-plus在继承BaseMapper时就已经自动注入，不必管它，如果看着碍眼就用@Repository注解放在接口上

package com.puls.mapper;
    
    import com.puls.enity.Account;
    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 AccountMapperTest { 
        @Autowired
        private AccountMapper accountMapper;
        @Test
        public void testSelect(){ 
            List<Account> list = this.accountMapper.selectList(null);
            System.out.println(list);
        }
    }

![在这里插入图片描述][20190915111027186.png]

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[20190915110603732.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/40d3a056129c4f25b80646b67640689c.png
[20190915111027186.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/04/18/dd3e929f1d1a4bec8737ba65d5edc39a.png