• MySQL版本8.0开始jdbc连接数据库的驱动变更：com.mysql.cj.jdbc.Driver
• 同时密码存储方式改变为 caching_sha2_password
• 需要修改MySQL配置文件中的default_authentication_plugin为mysql_native_password（不使用）
• 修改原有账户的加密方式：ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '新密码';

如果报错Unknown system variable ‘query_cache_size’，则为jdbc版本不一致导致，更换jdbc驱动版本即可

出现警告：WARN: Establishing SSL connection without server's identity verification is not recommended. According to MySQL 5.5.45+, 5.6.26+ and 5.7.6+ requirements SSL connection must be established by default if explicit option isn't set. For compliance with existing applications not using SSL the verifyServerCertificate property is set to 'false'. You need either to explicitly disable SSL by setting useSSL=false, or set useSSL=true and provide truststore for server certificate verification

• 只需要在数据库url后加上：useSSL=false 该问题我没有遇到

• 问题：java.sql.SQLException: The server time zone value

  • 时区错误，在url后添加：serverTimezone=UTC

mybatis的配置文件中直接使用&字符会出错，需用&来代替