我遇见的两个问题：执行generator时报错
问题一：
Failed to execute goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.5:generate (default-cli) on project miaosha: Unknown system variable 'query_cache_size'
解决一：
如果出现此问题，说明同行者你是在此课程出来后很久才开始学习！
所以只需要改变mysql的版本就可以了，我改成了8.0.27版本
<groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>8.0.27</version> </dependency>
问题二：
Failed to execute goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.5:generate (default-cli) on project miaosha: Execution default-cli of goal org.mybatis.generator:mybatis-generator-maven-plugin:1.3.5:generate failed: An API incompatibility was encountered while executing org.mybatis.generator:mybatis-generator-maven-plugin:1.3.5:generate: java.lang.NoSuchMethodError: org.mybatis.generator.internal.ObjectFactory.addResourceClassLoader(Ljava/lang/ClassLoader;)V
解决二：
将plugins中的下面的依赖，先拿到plugins外面一层，刷新maven，然后放回去，即可解决
<dependency> <groupId>org.mybatis.generator</groupId> <artifactId>mybatis-generator-core</artifactId> <version>1.3.5</version> </dependency>
