Question: So I have set up a mysql database that holds an image (more specifically a path to an image) and the images rank (starting at 0). I then created a web page that displays two images at random at a time. [Up till here everything works fine] I want my users to be able to click on one of the images that they like better and for that images rank to increase by +1 in the database.

How would I set that up? Please be as detailed as possible in your explanation. I am new to php and mysql.

Answer: 
Well i wasn't able to solve why the Between function didn't work - but mysql doesn't allow BETWEEN on floating point numbers either. So i'm going to assume that it's a similar reason. 

I changed my code to merely create it's own between statement. 

```
    NSPredicate *longPredicate = nil;
    NSPredicate *latPredicate = nil;
    if ([neCoordLong floatValue] > [swCoordLong floatValue])
    {
        longPredicate = [NSPredicate predicateWithFormat: @" longitude <= %@ AND longitude >= %@", neCoordLong, swCoordLong];
    }else {
        longPredicate = [NSPredicate predicateWithFormat: @" longitude <= %@ AND longitude >= %@", swCoordLong, neCoordLong];
    }
    if ([neCoordLat floatValue] > [swCoordLat floatValue])
    {
        latPredicate = [NSPredicate predicateWithFormat: @" latitude <= %@ AND latitude >= %@", neCoordLat, swCoordLat];
    }else {
        latPredicate = [NSPredicate predicateWithFormat: @" latitude <= %@ AND latitude >= %@", swCoordLat, neCoordLat];
    }

```

Hopefully this helps someone else
I don't see the exact cause either, and you haven't shown the code where the rest of boutiqueRequest's properties are set and the fetch fired (not that it matters unless you set the predicate again or something else funky), but the report

> 
> 2011-02-24 13:57:18.916 DL2[9628:207] -[NSCFNumber constantValue]: unrecognized selector sent to instance 0x954ba80
> 
> 
> 

indicates you're sending the message -constantValue to an object of class NSCFNumber (a toll-free NSNumber/CFNumber instance), which doesn't handle it. So I suggest you try using only portions of the predicate to find which doesn't and does cause some expression within the predicate to be substituted with an NSCFNumber instance.