PHP从数据库生成唯一ID

Question

In my project, i am generating a unique id from a table of database with taking largest integer value of an attribute 'serial_key' with adding 1 to that number. It is generating the unique index to add new tuple of records.

But this mechanism failed when i deployed the application on multiple PCs in intranet or internet, it was generating the same unique id on all different machines at an instant. And i have plenty of data in the server so i have to manage the same pattern of the id, since it was constructed taking a specific format. Please suggest how to resolve this problem. Thanks.

Answer 1

You can use the HiLo Algorithm, to generate unique keys. It can be tuned for performance or continous keys. If you implement it in all your clients (i guess java and php) you would get unique keys across as many keys as you like (or your database performance allows). You would also not be dependent on any database and if you tune it for throughput you wouldn't need much additional database querys.

See this SO-Answer.