/mysql-database-errors/

MySQL and Database Errors Troubleshooting

Fix database connection failures, crashed tables, slow queries, migration serialization issues, and WordPress database repair needs.

52 topics · 2 published guides

Common symptoms

Error establishing a database connection
Table crashed or marked as crashed
Query timeouts and lock waits
Site URL wrong after migration
Database too large or autoloaded options huge

Start here

01 Verify database credentials in wp-config.php
02 Confirm the database service is running
03 Export a backup before any repair
04 Check disk space on the database server

Most common problems

6 signals

Intermediate MySQL and Database Errors

Error establishing a database connection

Learn what causes “Error establishing a database connection,” how to recognize symptoms, and safe steps to diagnose and repair the problem.

Visitors or admins encounter: Error establishing a database connection

Intermediate MySQL and Database Errors

WordPress database needs repair

Learn what causes “WordPress database needs repair,” how to recognize symptoms, and safe steps to diagnose and repair the problem.

Visitors or admins encounter: WordPress database needs repair

On the board Intermediate

MySQL server has gone away

Learn what causes “MySQL server has gone away,” how to recognize symptoms, and safe steps to diagnose and repair the problem.

On the board Intermediate

MySQL table crashed

Learn what causes “MySQL table crashed,” how to recognize symptoms, and safe steps to diagnose and repair the problem.

On the board Intermediate

MySQL too many connections

Learn what causes “MySQL too many connections,” how to recognize symptoms, and safe steps to diagnose and repair the problem.

On the board Intermediate

WordPress database queries slow

Learn what causes “WordPress database queries slow,” how to recognize symptoms, and safe steps to diagnose and repair the problem.

All problems in this category

Showing 52 topics · 2 published guides

P1 · intermediate
Error establishing a database connection
Learn what causes “Error establishing a database connection,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
P1 · intermediate
WordPress database needs repair
Learn what causes “WordPress database needs repair,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
P2 · intermediate
MySQL server has gone away
Learn what causes “MySQL server has gone away,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P2 · intermediate
MySQL table crashed
Learn what causes “MySQL table crashed,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P2 · intermediate
MySQL too many connections
Learn what causes “MySQL too many connections,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P2 · intermediate
WordPress database queries slow
Learn what causes “WordPress database queries slow,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P2 · intermediate
WordPress database tables corrupted
Learn what causes “WordPress database tables corrupted,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P2 · intermediate
WordPress serialized data broken after migration
Learn what causes “WordPress serialized data broken after migration,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MariaDB upgrade error
Learn what causes “MariaDB upgrade error,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL access denied
Learn what causes “MySQL access denied,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL character set error
Learn what causes “MySQL character set error,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL collation error
Learn what causes “MySQL collation error,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL connection refused
Learn what causes “MySQL connection refused,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL data too long for column
Learn what causes “MySQL data too long for column,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL database backup failed
Learn what causes “MySQL database backup failed,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL database corrupted
Learn what causes “MySQL database corrupted,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL database migration failed
Learn what causes “MySQL database migration failed,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL database repair failed
Learn what causes “MySQL database repair failed,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL database restore failed
Learn what causes “MySQL database restore failed,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL deadlock found
Learn what causes “MySQL deadlock found,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL disk full
Learn what causes “MySQL disk full,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL duplicate entry error
Learn what causes “MySQL duplicate entry error,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL duplicate key error
Learn what causes “MySQL duplicate key error,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL export failed
Learn what causes “MySQL export failed,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL import failed
Learn what causes “MySQL import failed,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL incorrect string value
Learn what causes “MySQL incorrect string value,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL lock wait timeout exceeded
Learn what causes “MySQL lock wait timeout exceeded,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL max connections reached
Learn what causes “MySQL max connections reached,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL packet too large
Learn what causes “MySQL packet too large,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL query timeout
Learn what causes “MySQL query timeout,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL syntax error
Learn what causes “MySQL syntax error,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL table does not exist
Learn what causes “MySQL table does not exist,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL table is marked as crashed
Learn what causes “MySQL table is marked as crashed,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL temporary table full
Learn what causes “MySQL temporary table full,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL unknown column error
Learn what causes “MySQL unknown column error,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL unknown database
Learn what causes “MySQL unknown database,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL upgrade error
Learn what causes “MySQL upgrade error,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
MySQL version incompatibility
Learn what causes “MySQL version incompatibility,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress autoloaded options too large
Learn what causes “WordPress autoloaded options too large,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress database connection intermittent
Learn what causes “WordPress database connection intermittent,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress database credentials incorrect
Learn what causes “WordPress database credentials incorrect,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress database host incorrect
Learn what causes “WordPress database host incorrect,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress database is too large
Learn what causes “WordPress database is too large,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress database prefix incorrect
Learn what causes “WordPress database prefix incorrect,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress database search and replace failed
Learn what causes “WordPress database search and replace failed,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress database tables missing
Learn what causes “WordPress database tables missing,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress database update failed
Learn what causes “WordPress database update failed,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress database update required
Learn what causes “WordPress database update required,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress home URL incorrect in database
Learn what causes “WordPress home URL incorrect in database,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress options table too large
Learn what causes “WordPress options table too large,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress postmeta table too large
Learn what causes “WordPress postmeta table too large,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon
P3 · advanced
WordPress site URL incorrect in database
Learn what causes “WordPress site URL incorrect in database,” how to recognize symptoms, and safe steps to diagnose and repair the problem.
Coming soon

Related categories

Frequently asked questions

Is it safe to run WordPress database repair? +

Only after a verified backup. Repair can help crashed tables, but editing a live database without a backup risks permanent data loss.

Repair dispatch

Still Need Help Fixing Your Website?

If you are not comfortable editing website files, changing server settings, repairing a database, or troubleshooting a live website, professional help may prevent additional damage or downtime. We will review the problem before accepting the repair.

You will receive a clear explanation of the likely cause.
We will tell you if the issue falls outside our repair scope.
No additional work will be performed without approval.
A backup should be created whenever access and website condition allow it.

Emergency repair Request diagnosis

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