if field name exist then

luiddog

I'm trying to check if a field name exist for the following reason. I'm naming user's photos as either tom1.jpg, tom2.jpg, tom3.jpg with max of 5 photos. First, I had code checking the total_rows and then naming the pics +1 [i.e. if (total_rows = 1) { $picname = tom2 }] but then I realized that if the user deleted pic 3 then the code will try to name the new pic tom5, which already exists.

So I trying to find a way to check all the fields where username is tom then see which of the 5 names are not taken. Here is a laypersons translation:

1) Get all rows where username is Tom
2) Check all picname fields
3) If picname tom1, tom2, tom4, tom5 exists then $newpicname = tom3

Does this make sense?

devinemke

why don't you simply name the images using the primary key values from the table thereby eliminating the possiblilty of name collisions and not have to bother with any renaming. you can still easily enforce your 5 image limit by doing a simple COUNT() query.

luiddog

It's to save space. If the photos are named tom1, tom2...Then when uploading more photos the user will overwrite the previous photos. This way the user can't store more then 5 photos.

devinemke

you can timestamp each image and then simply delete the oldest one when uploading a new one (if there are already 5)

luiddog

Well they way I have it is that a user inputs a photo title and uploads the photo. The photo gets renamed, the title and photo location (/uploads/tom1.jpg) get put into a mysql table. Later the user can delete the mysql entry but the actual photo stays on the server. So the timestamp wouldn't work because a user might delete a photo entry that wasn't the oldest or newest.

devinemke

luiddog wrote:
So the timestamp wouldn't work because a user might delete a photo entry that wasn't the oldest or newest.

...yes...but one of the photos will always be the oldest regardless of which photos the user deleted.

let's back up here. you have a 1 to 1 relationship between image files and database records. the user can delete database records but you are still archiving the photo files. you want to impose a 5 photo limit but if a user uploads a 6th photo rather than display an error you want to delete the oldest photo. am i right up to this point? if so then again store the current date/time with every database record. when a user uploads a photo do a quick COUNT() query to see how many records they already have. if it is 5 then delete the oldest record before creating the new one. am i still missing something here?

luiddog

Thanks again for your help. Let me try to explain more about the setup and what needs to get done. User, Tom, uploads 5 photos. The mysql looks like this

Tom then deletes the entry for 'My Dog' but the actual photo 'tom3.jpg' remains on the server. Tom then uploads a new photo:

6 | My Cat | /uploads/tom3.jpg

I'm trying to find a way to name this new upload tom3.jpg. With the timestamp it would have deleted the entry for 'My Dog' then overwriten 'Me at home'.

Thanks again for your help. I've been searching for the solution.

devinemke

i am suggesting a different approach:

don't bother storing the filename. just use the primary key value from the table as the filenames. let's say Tom is user #28 from our user table. he uploaded 5 photos over the last week. the data might look like:

PicID | userID | date_time | Title
1 | 28 | 2006-09-01 08:02:33 | Me at home
2 | 28 | 2006-09-02 11:02:33 | My friend
3 | 28 | 2006-09-02 22:05:00 | My dog
4 | 28 | 2006-09-03 15:02:18 | My City
5 | 28 | 2006-09-11 02:08:33 | My Car

there will be 5 photos in /uploads/ called 1.jpg, 2.jpg, 3.jpg etc...

now Tom deletes "My Dog". so then next time he goes to upload a photo we now know that he only has 4 photos because we run a query like this:

SELECT COUNT(*) FROM photos WHERE userID = 28

thus we know that he has not exceeded his 5 photo limit and upload proceeds and a new file and db row are added:

PicID | userID | date_time | Title
1 | 28 | 2006-09-01 08:02:33 | Me at home
2 | 28 | 2006-09-02 11:02:33 | My friend
4 | 28 | 2006-09-03 15:02:18 | My City
5 | 28 | 2006-09-11 02:08:33 | My Car
6 | 28 | 2006-09-12 08:05:00 | My Cat

and the file 6.jpg is uploaded to /uploads/

after uploading that new photo he goes to upload another. when we run that same query we know that he has reached his 5 photo limit so we display an error saying "you have reached your limit. you must delete existing photos before you can upload any more". perhaps we can suggest that he delete "Me at home" since that is the oldest row in the db.

make sense?

luiddog

That makes sense (i forgot my db does have a username column). But wouldn't '3.jpg' still be on the server? Taking up space. That's why I have the 'tom3.jpg' setup so tom would overwite his previous photos with new ones.

The way I stop tom from uploading a 6th photo is by only showing the upload form if tom's total_rows < 5.

devinemke

luiddog wrote:
But wouldn't '3.jpg' still be on the server? Taking up space.

yes, but i thought that was what you wanted. if not then simply [man]unlink[/man] the file when you are deleting the database record.

luiddog

Genius. I never thought of that. Thanks again for you help.