How to re-assign AUTO_INCREMENT column for every row in a MySQL table using PHP

Question

I have an image gallery which website members can upload images to. When an image is uploaded, a MySQL row is written, containing various pieces of information about the ima

Answer 1

If you want the auto-incrementing id's to always be consecutive, let it go, it's a useless struggle.

If you just want to renumber once, that's easy:

Create a new table with the same layout:

CREATE TABLE mytable2 LIKE oldtable;

Copy all rows to the new table, remember to not select the auto_incrementing id, otherwise the old numbering will be retained.

INSERT INTO mytable2 (field2, field3, field4)
  SELECT field2, field3, field4 FROM oldtable ORDER BY oldtable.id;

RENAME oldtable archive;

RENAME mytable2 oldtable;

DROP archive;

You now have consecutive numbering.