database
MySQL Errors
MySQL errors use numeric codes: 1062 (duplicate entry), 1452 (foreign key fails), 1205 (lock wait timeout), 1213 (deadlock), 2002 (connection refused), 2013 (lost connection during query).
MySQL errors fall into client (2xxx) and server (1xxx) ranges. Connection issues (2002, 2003, 2005) are network/credentials. Server errors (1xxx) report SQL or storage engine problems. InnoDB deadlocks (1213) are auto-resolved — retry the failed transaction. Lock wait timeout (1205) usually means a long-running transaction is blocking.
Official docs
https://dev.mysql.com/doc/mysql-errors/8.0/en/
Support
https://dev.mysql.com/doc/