Got error: 1449: The user specified as a definer ('aaadb'@'%') does not exist when using LOCK TABLES

home/mysql/bin/mysqldump -u root -p aaa >./aaa.2020.03.09.sql

Enter password: 

mysqldump: Got error: 1449: The user specified as a definer ('sntvdb'@'%') does not exist when using LOCK TABLES

[root@s20190907 var]# 

[root@s20190907 var]# /home/mysql/bin/mysqldump -u root -p --lock-all-tables aaa >./aaa.2020.03.09.sql

Enter password: