Mysql: Auto increment in phpmyadmin

I have an existing database using PHP, MySQL and phpMyAdmin.

When users become a member on my website, I need the system to create a unique membership number for them using a five digit number. for e.g 83773. I guess it is like generating a random password except I only want numbers for my members. This ID number has to be unique to each member.

Would it be possible for me to set the primary key to auto_increment in my user table and set it to start at 10000 and then auto increment every time a member registers?

Also, is there a maximum number that the primary key ID number would go up to?

Is this a reliable and safe way to use the primary key ID number as a membership number?

 Answers

There is steps to make auto incriment for a column. I guess the phpMyAdmin version is 3.5.5 but not sure.

Click on Table > Structure tab > Under Action click on Change on the ppoup window scroll left and check A_I. Also make sure you have selected Nonefor Default

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Just run a simple MySQL query and set the auto increment number to whatever you want.

ALTER TABLE `table_name` AUTO_INCREMENT=10000

In terms of a maximum, as far as I am aware there is not one, nor is there any way to limit such number.

It is perfectly safe, and common practice to set an id number as a primiary key, auto incrementing int. There are alternatives such as using PHP to generate membership numbers for you in a specific format and then checking the number does not exist prior to inserting, however for me personally I'd go with the primary id auto_inc value.

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In phpMyAdmin, if you set up a field in your table to auto increment, and then insert a row and set that field's value to 10000, it will continue from there.

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You cannot set a maximum value (other than choosing a datatype which cannot hold large numbers, but there are none that have the limit you're asking for). You can check that with LAST_INSERT_ID() after inserting to get the id of the newly created member, and if it is too big handle it in your application code (e.g., delete and reject the member).

Why do you want an upper limit?