writing wp plugin:on deactivation it doesn't drop tables from db

[surferbloggy]

Hi I've wrote a plugin it works but on deactivation it doesn't drop the plugin tables from db
this is the code

$sql = "DROP TABLE IF_EXISTS 'TABLENAME'";
                $wpdb->query($sql);
                //$e = $wpdb->query($sql);
                //die(var_dump($e));

and i call that function this way
register_deactivation_hook(FILE, 'deactivate');

if i uncomment to show message error it tells me on deativation

bool(false)

whiy doesn't it drop the table?? could you help me to fix it??
thank you

[Tpojka]

Check this code. Bit different than yours.

[surferbloggy]

with this code it worked!!

global $wpdb;   //required global declaration of WP variable

    $table_name = $wpdb->prefix.$table_name;

    $sql = "DROP TABLE ". $table_name;

    $wpdb->query($sql);

thank you!!

[Tpojka]

Nice. Mark it as solved.