How to fix fatal error uncaught mysqli_sql_exception?

Troubleshooting Fatal Error: Uncaught mysqli_sql_exception

Encountering the “Fatal error: Uncaught mysqli_sql_exception” error in WordPress can be frustrating. This error can occur due to several factors, but it typically relates to database connectivity or invalid SQL queries. Here’s a comprehensive guide to help you troubleshoot and fix this error:

1. Verify Database Credentials

Start by confirming that the database credentials you have entered in your WordPress configuration file (wp-config.php) are correct. Check your database name, username, and password. If there are any errors, correct them and re-save the file.

2. Check MySQL Server Status

Ensure that your MySQL server is running and accessible. You can do this by connecting to the server using a command-line tool like MySQL Shell or by using a MySQL management tool like phpMyAdmin. If the server is not running, start it and then try reloading your website.

3. Inspect Custom Code and Plugins

Custom code or third-party plugins can sometimes interact with the database in ways that trigger the “Fatal error: Uncaught mysqli_sql_exception.” Check any recent code changes or plugin installations. If you suspect a specific plugin is causing the issue, try deactivating it and see if the error disappears.

4. Analyze SQL Queries

If the error is not caused by database credentials or custom code, the issue may lie in invalid SQL queries. Use a debugging tool like Xdebug to inspect the SQL queries being executed on your website. Look for any syntax errors or queries that are generating errors.

5. Check Database Tables

The “Fatal error: Uncaught mysqli_sql_exception” error can also occur when WordPress tries to access a database table that does not exist or has incorrect permissions. Use a tool like phpMyAdmin to inspect your WordPress database tables and ensure they exist and have the correct permissions.

6. Repair the Database

If you suspect the database is corrupted, you can try repairing it. Connect to your database server using a command-line tool or phpMyAdmin and run the following command:

mysql> REPAIR TABLE table_name;

7. Restore from Backup

If you have recently made changes to your database or website files and now encounter the “Fatal error: Uncaught mysqli_sql_exception,” consider restoring your website from a backup. This will revert your website to a previous state and potentially resolve the issue.

8. Seek Professional Help

If you are unable to resolve the issue on your own, contact your hosting provider or a WordPress developer for help. They can assist you in identifying and fixing the underlying cause of the error.

By following these steps, you can effectively troubleshoot and resolve the “Fatal error: Uncaught mysqli_sql_exception” in WordPress and ensure your website runs smoothly.