(mysql, php) How to get auto_increment field value before inserting data?

Question

I\'m uploading image file to storage server. Before uploading I should compose filename, which contains AUTOINCREMENT VALUE in it (for example, 12345_filename.jpg).

Answer 1

There is no solution. You get the auto-increment value when you insert a new row, full stop. Inserting and deleting won't help, since the next auto-increment value will be one higher. Do to possibly multiple clients talking to the database at the same time, you can't predict the next value since it might be incremented between your guessing and your actual insert.

Find a different solution. Either insert a row and update it later, or generate an id for the filename that's independent of the auto-increment id.