Call to undefined method Illuminate\Database\Query\Builder::colFunction()

i am geting this called to undeifne method and i am totally new dont now how to define method this is route line Route::post('/colFunction','Controller@colFunction'); this is my controller function

function colFunction(Request $req)
{
 $column =$req->input('column');

 $data =array('column'=>$column);
 \DB::table('column')->colFunction($data);
}

via Chebli Mohamed