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CodeIgniter: Resolving "Unable to Connect to Database" Error with MySQL Driver
Problem Statement:
When attempting to switch from the MySQL driver to the MySQLi driver in CodeIgniter, users encounter the following error message:
Unable to connect to your database server using the provided settings.
Configuration Details:
The provided database configuration settings are as follows:
$hostname = 'localhost'; $username = 'myusernamegoeshere'; $password = 'mypasswordgoeshere'; $database = 'mydatabasenamegoeshere'; $db['default']['dbdriver'] = 'mysqli'; $db['default']['port'] = "3306";
Solution:
The issue is likely related to PHP configuration. To debug the database connection, follow these steps:
Step 1: Enable Database Connection Error Diagnostics
Add the following code to the end of your database.php configuration file:
... ... ... echo '<pre class="brush:php;toolbar:false">'; print_r($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 '
Step 2: Debug Database Connection Attempt
Navigate to your CodeIgniter installation directory and run the following command to debug the database connection attempt:
php -f ./system/index.php db debug
Step 3: Analyze Output
The command will output detailed information about the database connection attempt, including any errors encountered. Review the output to identify the root cause of the connectivity issue.
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