Remember an error in MySQL: the user specified as a definer ('mysql.infoschema '@' localhost ') does not exist

Recently, it will be used before mysql5.5 Upgrade to mysql8.0, It can be used normally on the first day , After a few days of no use , An error is reported when logging in ：The user specified as a definer ('mysql.infoschema'@'localhost') does not exists , It means infoschema No users , I think I haven't done anything these days , Just look online , I tried every method , Or not , Or report some inexplicable mistakes in the process , At a time when I am completely disillusioned , Suddenly found this big guy's blog , Links are as follows ：

Remember a mysql User disappearance problem - the endless sea of tribulations , Looking back is a realm - ITeye Blog

  This problem can be solved according to the steps of the boss