I would like to get the value of the column `uid` from **all** rows where the value of the column `city` is `london`.

I have tried it like this:

```
$this->getDoctrine()->getRepository(Personal::class)->findOneBy(['city' => 'london']);

```

but then I get an object from only 1 row. What I need is simply an array that looks kind of like this:

> 
> array(3) { [0]=> int(1) [1]=> int(2) [2]=> int(3) }
> 
> 
>