CodeIgniter Database Connection Error: How Can I Diagnose and Fix 'Unable to connect to your database server'?

CodeIgniter Database Connectivity Error: Diagnose and Resolve

The "Unable to connect to your database server using the provided settings" error message in CodeIgniter is a common indicator of database connection issues. To resolve this, we must identify the root cause of the problem.

Database Configuration

Verify that your database configuration settings in application/config/database.php are correct. Ensure that the dbdriver is set to 'mysqli', hostname, username, password, and database name are accurate. Additionally, ensure that the port is specified correctly, as in your case, it is set to "3306".

PHP Configuration

An additional check involves debugging the PHP configuration. At the end of database.php, add the following snippet:

...
echo '<pre class="brush:php;toolbar:false">';
print_r($db['default']);
echo '

'; echo 'Connecting to database: ' .$db['default']['database']; $dbh = mysql_connect( $db['default']['hostname'], $db['default']['username'], $db['default']['password'] ) or die('Cannot connect to the database because: ' . mysql_error()); mysql_select_db($db['default']['database']); echo '
Connected OK:'; die('file: ' .__FILE__ . ' Line: ' .__LINE__); // FOR DEBUGGING

Run your application, and you will see detailed information about your database configuration and connection attempts. If successful, it will display a "Connected OK" message.

Other Considerations

• Firewall: Ensure that your firewall is not blocking connections to the database server.
• Server Status: Verify that the database server is running and accepting connections.
• SQL Syntax: If you have recently made any changes to your SQL syntax, double-check their validity.

By following these steps, you can effectively diagnose and resolve the "Unable to connect to your database server using the provided settings" error in CodeIgniter.

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