I need your help on how am I going to convert the following Mysql to Doctrine.

```
select * from calendar_data as c where LEAST(c.end, end) - GREATEST(c.start, start) > 0;

```

I tried this one:

```
$qb = $em->createQueryBuilder();
$query = $qb->select('items')
                ->from('\Admin\Entity\CalendarData','items')
                ->where('LEAST(items.end, :end) - GREATEST(items.start, :start) > 0')
                ->setParameter('start',$start)
                ->setParameter('end', $end);

```

(Given that `$start` and `$end` is already provided)

and I have the following error:

```
{
 "type": "http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html",
 "title": "Internal Server Error",
 "status": 500,
 "detail": "[Syntax Error] line 0, col 57: Error: Expected known function,   got 'LEAST'"
}

```

How should I do that?

This is the generated sql to my question: 

[Mysql query to determine if the given datetime is included in the datetime interval](https://stackoverflow.com/questions/42801817/mysql-query-to-determine-if-the-given-datetime-is-included-in-the-datetime-inter)