creat unique numbers on creation

[dark-angel]

well i need to know how to code this, when a user creats an account i want php to creat a number for its id. the user register, it goes and check in the id colum under the memeber table to check to see if 1 is taken, if its taken looks for 2 and so on until he finds an id thats not taken then insert it in the table alon with the rest of the info supplied.

[[deleted]]

This is not the way to do it.
Let your database create the numbers using the auto_increment or 'serial' properties of the primary key of your table.
That way you can just create a new row in the table and the database will create a new unique id and give it back to you.

Never try to make a unique id by yourself, because that's impossible in a multi-user environment.

[dark-angel]

thanks... its working woohoo! but one thing how does it add id auto? cause it indicated 2 while it was my only entry, or is it ramdome or if i all ready add info earlyer then deleted still keeps the id even if it was earased?

[[deleted]]

it's auto increment. That means that for every new row it will increase the number by one. It never goes back to numbers that have already been used (hence the word 'unique')
This also means that the column that contains this value must be of the right datatype. For example, if you use MySQL's TINYINT, you can only generate 127 numbers and then you've reached the limit of what TINYINT can hold and you can't insert any more rows (because there are no more auto numbers available)

[dark-angel]

then how do i go behond 127, cause im making a webpage for a guild, every one knows guild change a lot members leaves come back join and so on so how do i go behond 127?

[[deleted]]

Just make sure that the datatype of the column you are using for the auto-id's is of the INT type, that can go beyond 2 billion numbers.