Database select error

Question

Database select error its my problem and when I restart my mysql to fix this error this problem solve but after 30 minutes or after hours again this error happen again.

I put link here screenshot from ssh [putty] of errors what should i do? for what reason this happen?

tail -f /var/log/mysqld.log
120813 17:33:57 InnoDB: Completed initialization of buffer pool
120813 17:33:57 InnoDB: highest supported file format is Barracuda.
120813 17:33:57  InnoDB: Waiting for the background threads to start
120813 17:33:58 InnoDB: 1.1.8 started; log sequence number 63473783633
120813 17:33:58 [ERROR] Column count of mysql.db is wrong. Expected 22, found 20. Created with MySQL 50092, now running 50516. Please use mysql_upgrade to fix this error.
120813 17:33:58 [ERROR] mysql.user has no `Event_priv` column at position 29
120813 17:33:58 [ERROR] Event Scheduler: An error occurred when initializing system tables. Disabling the Event Scheduler.
120813 17:33:58 [Note] /usr/libexec/mysqld: ready for connections.
Version: '5.5.16'  socket: '/var/lib/mysql/mysql.sock'  port: 3306  MySQL Community Server (GPL) by Remi

Answer 1

1. reinstall your mysql but idont recommend use mysql_upgrade
2. check user table in mysql db it seems it has missing column or row
3. Repair Corrupted Databases use mysqlcheck -rA -u root -p

Answer 2

Run mysqlcheck, see here -- http://scottlinux.com/2012/06/09/use-mysqlcheck-to-optimize-and-repair-mysql-databases/

Also, check if your RAM/disks have no issues. Also, upgrade to the latest release of whatever version of MySQL you are running.

Answer 3

If you have recently upgraded mysql, you may be missing some columns in the system tables or something just didn't upgrade correctly. take a look at mysql_upgrade. earlier versions of mysql, you'd have to use mysql_fix_privilege_tables. it was removed in 5.5 i believe.

don't forget to back up you database(s) before you do anything in your db.