Reorder / reset auto increment primary key

Question

I have a MySQL table with an auto increment primary key. I deleted some rows in the middle of the table. Now I have, for example, something like this in the ID column: 12, 1

Answer 1

I had the same doubts, but could not make any changes on the table, I decided doing the following having seen my ID did not exceed the maximum number setted in the variable @count:

SET @count = 40000000;
UPDATE `users` SET `users`.`id` = @count:= @count + 1;

SET @count = 0;
UPDATE `users` SET `users`.`id` = @count:= @count + 1;

ALTER TABLE `users` AUTO_INCREMENT = 1;

The solution takes, but it's safe and it was necessary because my table owned foreign keys with data in another table.

Answer 2

in phpmyadmin

note: this will work if you delete last rows not middle rows.

goto your table-> click on operations menu-> goto table options->change AUTO_INCREMENT to that no from where you want to start.

your table autoincrement start from that no.

try it.

Answer 3

Or, from PhpMyAdmin, remove "AutoIncrement" flag, save, set it again and save.this resets it.