Database Connection Errors

This guide helps you troubleshoot WordPress database connection errors on Pressidium, including connection failures, database credential issues, and database-related WordPress errors.

Database connection errors can prevent your WordPress site from loading or stop you from accessing the WordPress admin area.

Use this guide to identify the most likely cause, complete basic checks, and decide when to contact Support.

Use this guide when:

• Your site shows “Error establishing a database connection.”
• Your site does not load because WordPress cannot connect to the database.
• WordPress admin is not accessible because of a database error.
• You see database-related error messages.
• Pages fail because database queries cannot complete.
• The issue started after a configuration, migration, restore, or credential change.

The page contains:

• Common symptoms of WordPress database connection errors
• Common causes, including database credentials, server availability, resource limits, and WordPress configuration issues
• Diagnostic steps to narrow down the cause
• Common issues and solutions
• Verification checks after applying a fix
• Best practices for reducing database-related risk
• Support guidance and related next-step articles

Common symptoms

Database connection issues usually appear in one of these ways:

• Database connection error: WordPress shows “Error establishing a database connection.”
• Site not loading: The frontend fails because WordPress cannot reach the database.
• Admin not accessible: /wp-admin does not load because the database connection fails.
• Database error messages: WordPress or PHP shows database-related warnings or errors.
• Query failures: Some pages load, but features that depend on database queries fail.
• Intermittent failures: The site works sometimes but fails during traffic spikes or high load.

Common causes

Incorrect database credentials

WordPress connects to the database using values stored in wp-config.php.

A connection error can happen if one of these values is incorrect:

• Database name
• Database username
• Database password
• Database host
• Table prefix, if the site expects a different prefix

Database server unavailable

The database service may be unavailable, overloaded, restarting, or unreachable.

This can affect the whole site because WordPress needs the database to load pages, settings, users, posts, and plugin data.

Resource limits or high load

High traffic, heavy queries, plugin activity, or background tasks can increase database load.

When database resources are exhausted, WordPress may show connection errors, slow responses, or intermittent failures.

WordPress configuration issue

A syntax error, incorrect value, or damaged configuration in wp-config.php can prevent WordPress from connecting to the database.

This is more likely after manual edits, migrations, restores, or environment changes.

Database table issue

If database tables are missing, damaged, or inconsistent after a migration or restore, WordPress may fail to load normally.

This may appear as a database error, a missing table message, or a partial site failure.

Origin or hosting issue

The database belongs to the origin hosting environment. If the origin environment has a database service issue, EDGE cannot fix the database connection itself.

EDGE can reduce origin load for cacheable traffic, but uncached WordPress requests still depend on the origin and database being healthy.

Diagnostic steps

Step 1: Confirm the error

Check the exact error shown on the site.

Look for:

• “Error establishing a database connection”
• Database authentication errors
• Connection timeout messages
• Missing table errors
• PHP warnings that mention database access

Take a screenshot or copy the exact message before making changes.

Step 2: Check whether the whole site is affected

Test:

• The homepage
• A few internal pages
• /wp-admin
• /wp-login.php

If the whole site shows the same database error, the issue is likely database-wide.

If only some pages fail, the issue may be related to a plugin, query, table, or specific WordPress feature.

Step 3: Check recent changes

Review what changed before the error started.

Check for:

• Site migration
• Database restore
• WordPress core update
• Plugin or theme update
• Manual edit to wp-config.php
• Password or credential change
• Domain or environment change
• Recent high-traffic event

Step 4: Review wp-config.php

Check the database connection values in wp-config.php.

Review:

• DB_NAME
• DB_USER
• DB_PASSWORD
• DB_HOST
• $table_prefix

Step 5: Check database availability

Check whether the database service is available from the hosting environment.

If you cannot verify this from your dashboard or tools, contact Support and provide the error message, timestamp, and affected domain.

Step 6: Review logs

Check available error logs for database-related messages.

Look for:

• Access denied errors
• Unknown database errors
• Connection refused errors
• Connection timeout errors
• Missing table errors
• PHP fatal errors involving database calls

Common issues and solutions

The site shows “Error establishing a database connection”

Likely causes:

• Incorrect database credentials
• Database server unavailable
• Database service overloaded
• wp-config.php configuration issue

Resolution steps:

1. Confirm the exact error message.
2. Check whether the issue affects the whole site.
3. Review recent changes.
4. Check wp-config.php for database connection values.
5. Contact Support if the credentials appear correct but the issue continues.

The issue started after a migration or restore

Likely causes:

• Database credentials do not match the new environment.
• Database import did not complete correctly.
• Tables are missing or use an unexpected prefix.
• The restored files and database do not belong to the same site version.

Resolution steps:

1. Confirm when the migration or restore completed.
2. Check whether the database import completed successfully.
3. Review wp-config.php values.
4. Confirm the expected table prefix.
5. Restore from a known good backup if needed.
6. Contact Support if the database state is unclear.

The issue started after editing wp-config.php

Likely causes:

• Incorrect database value.
• Syntax error.
• Missing quote, semicolon, or constant.
• Wrong database host value.

Resolution steps:

1. Reopen wp-config.php.
2. Check the edited lines carefully.
3. Restore the previous working version if available.
4. Test the site again.
5. Contact Support if you cannot identify the change.

The site fails intermittently

Likely causes:

• High database load.
• Resource pressure.
• Heavy plugin queries.
• Traffic spikes.
• Background tasks or cron activity.

Resolution steps:

1. Note the time periods when the issue appears.
2. Check whether the issue matches traffic spikes or scheduled tasks.
3. Review recent plugin or theme changes.
4. Check logs for repeated database timeouts.
5. Contact Support with timestamps and affected URLs.

Only some pages show database errors

Likely causes:

• Plugin-specific query failure.
• Missing or damaged database table.
• Theme or custom code issue.
• A specific page triggering heavy database queries.

Resolution steps:

1. Identify the affected URLs.
2. Check whether the same plugin or feature is used on those pages.
3. Review error logs for missing table or query errors.
4. Disable the suspected plugin only if you have a safe way to do so.
5. Contact Support if the issue affects important site functionality.

WordPress admin is not accessible

Likely causes:

• Database connection failure.
• User/session data cannot be read.
• Plugin or database table issue.
• Admin-specific query failure.

Resolution steps:

1. Test the frontend and /wp-admin.
2. Confirm whether both show the same database error.
3. Review logs for admin-related database messages.
4. Check recent plugin or database changes.
5. Contact Support if you cannot access admin to continue troubleshooting.

Verification

After applying a fix, verify that the site works correctly.

Check that:

• The homepage loads.
• Several internal pages load.
• /wp-admin opens.
• You can log in to WordPress.
• Pages that previously failed now load correctly.
• Error logs no longer show repeated database connection errors.
• The issue does not return after several minutes of normal browsing.

Best practices

• Keep recent backups before making database or configuration changes.
• Avoid editing wp-config.php unless you know the correct values.
• Record the original value before changing any database setting.
• Test migrations and restores before switching live traffic.
• Keep WordPress core, plugins, and themes updated.
• Remove unused plugins that create heavy database load.
• Monitor recurring errors after high-traffic events or major updates.

Need help?

Contact Support if:

• The site shows “Error establishing a database connection.”
• The database credentials appear correct but the site still fails.
• The issue started after a migration, restore, or configuration change.
• You cannot access WordPress admin.
• The issue is intermittent and you need help checking logs.
• You see missing table, timeout, or authentication errors.
• You are not sure whether it is safe to edit wp-config.php.

Include the following details:

• The affected domain.
• The exact error message or screenshot.
• The time the issue started.
• Whether the issue affects the frontend, admin area, or both.
• Any recent changes, migrations, restores, plugin updates, or manual edits.
• Steps you already tried.
• Relevant log entries, if available.

Where to go next

• Troubleshoot a blank or fatal-error page: White Screen of Death
• Troubleshoot login or admin-area failures: Admin Access Issues
• Export a database before making changes: Backup / Export Database
• Import a database dump safely: Import a MySQL Dump
• Run a database search and replace: Database Search and Replace
• Restore a known good backup: Restore an Instant Backup