1669
MySQLERRORCommonSchemaHIGH confidence
Column count in internal system table does not match expected value
Production Risk
High — authentication and grant operations may fail if mysql.user is corrupted.
What this means
An internal MySQL system table has a different number of columns than expected, usually because mysql_upgrade has not been run after a server upgrade.
Why it happens
- 1MySQL server was upgraded without running mysql_upgrade.
- 2System table definition was manually altered.
How to reproduce
trigger — this will error
trigger — this will error
-- Accessing mysql.user or other system tables after a partial upgrade
expected output
ERROR 1669 (HY000): Column count of mysql.user is wrong. Expected 45, found 43. The table is probably corrupted.
Fix
Run mysql_upgrade
Run mysql_upgrade
mysql_upgrade -u root -p
Why this works
mysql_upgrade adds any missing columns to system tables to match the current server version.
What not to do
✕
Version notes
Sources
Official documentation ↗
MySQL 8.0 — 1669 ER_COL_COUNT_DOESNT_MATCH_CORRUPTED_V2
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