How to assign unique names to images?

Question

I'm writing a web application where users can upload images. I wonder what's the best practice of assigning unique names to images ? I thought MD5 can ben useful and enough, but since each image has an owner, do I have to use MD5 ? I mean it could be enough to rename with Userid + imagename + creationdate ?

score 3 · Accepted Answer · answered Feb 23 '11 at 02:27

3

Your database gives you a unique ID for each record. Though there are many different ways to do what you want, it is usually best to use this ID as a prefix/suffix to the name of the image. So, for these records:

ID  |  name
15    image.png
23    image.png

you could display something like: 15_image.png, 23_image.png

answered Feb 23 '11 at 02:27

Eelvex

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@Aleksi: you insert once, so it's not a big deal to ask it (if you want to save that way) and when you search, it's better to search by ID anyway. – Eelvex Feb 23 '11 at 02:30
1

I agree that it's not a big deal, but when you consider the users with lowest skill level, it is a bit misguided to tell them that the ID justs pops up. You have to design for it and create a sequence or an auto-increment declaration depending of the DBMS is in use i.e. you'll have to ask for it as it's not given. – Aleksi Yrttiaho Feb 23 '11 at 02:37
@Aleksi: you're right, I haven't thought of it that way. I'll leave my answer as it is, though, until we see some more comments from the questioner. – Eelvex Feb 23 '11 at 02:43

score 0 · Answer 2 · answered Feb 23 '11 at 02:25

No, it would not be enough as the user might want to upload several images with the same name.

The easiest solution is to use a sequence number with the image name. You can be certain that there is no other image with the same name and there will never be one. With a hash function there is always an ever so slight chance of collision.

How to assign unique names to images?

2 Answers2