mybatisdemo（黑马）

需求：对一张user表进行增删改查

准备：

1. 新建一个SpringBoot项目命名为mybatisdemo
2. 在pom.xml文件中引入依赖（mybatis、mysql、lombok、druid）
3. 在application.yaml文件中配置数据库等信息
4. 新建包名为mapper，其下建一个接口名为UserMapper
5. 新建包名为pojo，其下建一个实体类名为User
6. 编写测试类
7. 新建一个名为mybatis的数据库，新建一个名为user的表

一、准备好项目，目录结构如下

二、引入依赖，配置信息

<?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>3.4.7</version><relativePath/> <!-- lookup parent from repository --></parent><groupId>com.rzl</groupId><artifactId>mybatisdemo</artifactId><version>0.0.1-SNAPSHOT</version><name>mybatisdemo</name><description>mybatisdemo</description><url/><licenses><license/></licenses><developers><developer/></developers><scm><connection/><developerConnection/><tag/><url/></scm><properties><java.version>17</java.version></properties><dependencies><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-data-jdbc</artifactId></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>3.0.4</version></dependency><dependency><groupId>com.mysql</groupId><artifactId>mysql-connector-j</artifactId><scope>runtime</scope></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter-test</artifactId><version>3.0.4</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid-spring-boot-3-starter</artifactId><version>1.2.20</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId></dependency></dependencies><build><plugins><plugin><groupId>org.springframework.boot</groupId><artifactId>spring-boot-maven-plugin</artifactId></plugin></plugins></build></project>

三、编写实体类User

四、编写接口

五、编写测试类

package com.rzl;
import com.rzl.mapper.UserMapper;
import com.rzl.pojo.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;@SpringBootTest
class MybatisdemoApplicationTests {@Autowiredprivate UserMapper userMapper;@Test//删除数据public void testDelete() {userMapper.delete(3);}//新增数据@Testpublic void testInsert() {User user = new User();user.setUsername("任佳佳");user.setPassword("789");user.setGender("女");user.setAddr("贵州");userMapper.insert(user);}//更新数据@Testpublic void testUpdate(){User user = new User();user.setId(2);user.setUsername("任san");user.setPassword("987");user.setGender("男");user.setAddr("江苏");userMapper.update(user);}//查询数据@Testpublic void testSelect(){userMapper.list("san");}
}

最后运行，成功后，数据库会变成这样：