centos7 mysql 8 降到 5.7 错误问题

mysql -V rpm -qa | grep mysql

rpm -qa | grep mariadb

先卸载 mariadb 

不小心安装了mysql8 （用着不顺）

重装mysql 5 之后一直启动失败

2022-09-15T10:02:14.614010Z 0 [ERROR] [FATAL] InnoDB: Table flags are 0 in the data dictionary but the flags in file ./ib
data1 are 0x4800!

 cd /var/lib/

rm -rf ./mysql

systemctl start mysqld.service 重启

该目录下缓存的配置项不匹配 得删掉