Auto Increment skipping numbers?

Question

Note: I\'m new to databases and PHP

I have an order column that is set to auto increment and unique.

In my P

Answer 1

auto increment doesn't care, if you delete some rows - everytime you insert a row, the value is incremented.

If you want a numbering without gaps, don't use auto increment and do it by yourself. You could use something like this to achive this for inserting

INSERT INTO tablename SET
    `order` = (SELECT max(`order`) + 1 FROM (SELECT * from tablename) t),
    ...

and if you delete a row, you have to rearange the order column manually