Error: Uncaught Error: Undefined class constant 'MYSQL_ATTR_USE_BUFFERED_QUERY' in /var/www/html/myproject/includes/database/mysql/database.inc:56

Question

I am working with drupal 7 and I install drush V7.4.0 but when i run drush cc all I am getting this error : Error: Uncaught Error: Undefined class constant 'MYSQL_ATTR_USE_BUFFERED_QUERY' in /var/www/html/myproject/includes/database/mysql/database.inc:56

Answer 1

You are missing some sort of php support for mysql.

Examine:

print phpinfo();

and see if there is a reference to PDO or pdo_mysql . Generic install for php support (it includes the pdo_mysql extension) can be done with:

sudo apt-get install php{digits}-mysql

where {digits} needs to be replaced by your php version (could be 5, 6, 7.0, 7.1). After adding this you need to include the module and need to restart apache.

Answer 2

Check whether MYSQL PDO extension is enabled/installed by looking into your <?php echo phpinfo(); ?>

Probably not: So please install the below extension by running the command in Ubuntu 18.04: In case php.7.3

$  sudo apt-get install php7.3-mysql
$  sudo phpenmod pdo_mysql
$  sudo service apache2 restart