Returns availability for a given times/dates

Question

I have been struggling with a function that returns true or false if the DateTime the user requests overlaps with any of DateTime already in MYSQL database.

The situation is that users can submit car rental requests via iOS app and it comes in DateTime format 2014-04-02 08:49:43. I'm using Laravel as an API to manage backend. The table for Reservation is:

Schema::table('reservations', function($table)
{
    $table->dateTime('from_date')->nullable();
    $table->dateTime('to_date')->nullable();
});

So I tried many methods but reserving date and time without overlapping have been a pain for the past 2 days. The closest thing I got to, is this function and I think (hopefully) this function is right but something is missing.

 public function isSlotAvailable(Request $request) {
    $appointments = Reservation::all();
    $from = $request->from;
    $to = $request->to;

    foreach ($appointments as $appointment) {
        $eventStart = Carbon::instance(
            new DateTime($appointment['dt_start'])
        );

        $eventEnd = Carbon::instance(
            new DateTime($appointment['dt_end'])
        )->subSecond(1);

        if ($from->between($eventStart, $eventEnd) || 
            $to->between($eventStart, $eventEnd)   || 
            ($eventStart->between($from, $to) && $eventEnd->between($from, $to))) 
        {
            return false;
        }
    }

    return true;
}

The error I get from this function is:

Call to a member function between() on string

I'd really appreciate any help.

Answer 1

Rather than try to use between() you could check

if($from<$eventEnd && $to>$eventStart){
    return false;
}

This should return false for all cases except where your new event both starts and ends before the start of the existing event, or you new event both starts and ends after your existing event.

This assumes that you have already checked that $from<$to and $eventStart<$eventEnd in all cases, which I hope is the case!