mysql错误

Can't connect to local MySQL server through socket '/tmp/mysql.sock'

rm -rf /var/lib/mysql
sudo systemctl start mysqld
sudo systemctl status mysqld

mysql删除数据库提示Error dropping database

https://blog.csdn.net/free_xiaochen/article/details/84300600

有外键约束，不能删除表（Cannot delete or update a parent row: a foreign key constraint fails）

// 先设置外键约束检查关闭 
SET foreign_key_checks = 0;  
 // 删除表，如果要删除视图，也是如此
drop table table1; 
// 开启外键约束检查，以保持表结构完整性
SET foreign_key_checks = 1; 

https://blog.csdn.net/u010429286/article/details/79042886

Native table 'performance_schema'.'???' has the wrong structure（通常是mysql更新或重装出现）

sudo mysql_upgrade -u root -p
// 重启
sudo systemctl stop mysqld
sudo systemctl start mysqld

not allowed to connect to this MySQL server

添加远程ip访问权限

GRANT ALL PRIVILEGES ON . TO 'root'@'192.168.199.99' IDENTIFIED BY '密码' WITH GRANT OPTION;
flush privileges;

mysql安装在centos7报错ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

https://blog.csdn.net/mo_qi_qi/article/details/84573350

MySQL 5.7 创建用户报错 ERROR 1805 (HY000): Column count of mysql.user is wrong

mysql_upgrade -uroot -p
http://blog.itpub.net/26506993/viewspace-2154944/

ERROR 1682 (HY000): Native table 'performance_schema'.'threads' has the wrong structure

• 都是mysql重装，版本升级导致的问题

mysql_upgrade -uroot -p