error when calling to_database method

[maxlibin]

$csvClass = new CSV;
$csvClass = CSV::from_file('public/uploads/'.$filename);
$csvClass->to_database('csv', $table_already_exists = false, $clear_existing_records = false);

SQLSTATE[42000]: Syntax error or access violation: 1166 Incorrect column name ''

SQL: CREATE TABLE csv (VARCHAR(200) NOT NULL, VARCHAR(200) NOT NULL)

Bindings: array (
)

/Users/libin/Sites/laravel/laravel/database/connection.php on line 264
Stack Trace:
#0 /Users/libin/Sites/laravel/laravel/database/connection.php(184): Laravel\Database\Connection->execute('CREATE TABLE c...', Array) #1 /Users/libin/Sites/laravel/laravel/database/schema.php(115): Laravel\Database\Connection->query('CREATE TABLE c...')
#2 /Users/libin/Sites/laravel/bundles/dbutil/libraries/dbutil.php(60): Laravel\Database\Schema::execute(Object(Laravel\Database\Schema\Table))
#3 /Users/libin/Sites/laravel/bundles/laravel-csv-master/libraries/csv.php(287): DBUtil::make('csv', Array)
#4 /Users/libin/Sites/laravel/application/controllers/upload.php(32): CSV->to_database('csv', false, false)
#5 [internal function]: Upload_Controller->post_index()
#6 /Users/libin/Sites/laravel/laravel/routing/controller.php(325): call_user_func_array(Array, Array)
#7 /Users/libin/Sites/laravel/laravel/routing/controller.php(285): Laravel\Routing\Controller->response('index', Array)
#8 /Users/libin/Sites/laravel/laravel/routing/controller.php(165): Laravel\Routing\Controller->execute('index', Array)
#9 /Users/libin/Sites/laravel/laravel/routing/route.php(153): Laravel\Routing\Controller::call('upload@(:1)', Array)
#10 /Users/libin/Sites/laravel/laravel/routing/route.php(124): Laravel\Routing\Route->response()
#11 /Users/libin/Sites/laravel/laravel/laravel.php(167): Laravel\Routing\Route->call()
#12 /Users/libin/Sites/laravel/public/index.php(34): require('/Users/libin/Si...')
#13 {main}