Re: Create unique non-autoincrement key for 700,000 records?

At 11:29 PM -0500 12/15/08, Rob Gould wrote:

update mytable set hash_field = md5(AutoIdField + unix_timestamp()) I _think_ I understand that - - - - but what does the "AutoldField" variable mean?

He probably intends AutoIdField to be a stand-in for whatever your current auto increment column is called. You probably want to create a unique index - http://dev.mysql.com/doc/refman/5.0/en/create-index.html - on hash_value as well for (1) performance and (2) to ensure against duplicate values (which are, admittedly, pretty unlikely). Another alternative is to use the uuid() function - http://dev.mysql.com/doc/refman/5.0/en/miscellaneous-functions.html#function_uuid - instead of the md5() above, eg update mytable set unique_field=uuid(); - steve

On Monday, December 15, 2008, at 09:37PM, "Bastien Koert" <phpster@gmail.com> wrote:

On Mon, Dec 15, 2008 at 9:29 PM, Rob Gould <gouldimg@mac.com> wrote:

I have a mySQL database with 700,000 records in it, which are presently keyed with an "auto-increment" field. What I'd like to do is create another field with a field where each and every record number has a unique keyvalue. Example: "su5e23vlskd" for records 1, and "34fdfdsglkdj4" for record 2. All that matters is that it's unique, and isn't a number that can be guessed or an "autoincrement" number, where a hacker can just figure out the keyvalue by incrementing numbers. It doesn't matter to me if each keyvalue field is just numbers, or a number/letter combination - - - all that matters is that each keyvalue field is unique. Is there an automatic way that mySQL could do that, or would I need to write a php script to somehow go through each record and create this unique value? -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php

update mytable set hash_field = md5(AutoIdField + unix_timestamp()) -- Bastien

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