Uncaught Error: Undefined class constant 'MYSQL_ATTR_INIT_COMMAND'

问题：php7.4一直报错Uncaught Error: Undefined class constant 'MYSQL_ATTR_INIT_COMMAND'

方法：

vim /etc/php/7.4/fpm/php.ini
打开下面配置，没有添加
extension=mysqlnd
extension=pdo
extension=pdo_mysql
注：确保已经安装php7.4-mysql

修改完后重启php

sudo systemctl restart php7.4-fpm
sudo systemctl status php7.4-fpm