How to update id set from 1?

Question

I have an id i.e primary key and auto increment. Is there any query to update my existing id and make my id start from 1 and next id 2

Answer 1

Is there any query to update my existing id and make my id start from 1 and next id 2 and so on

What you can do is transfer the content of your table to another table. Reset the auto increment counter, insert your data back into the original table but let MySQL assign the primary key.

Assuming your table name is mytable You do it like this:

CREATE TABLE mytable_tmp select * from mytable;
TRUNCATE TABLE mytable;
ALTER TABLE mytable AUTO_INCREMENT = 1;
INSERT INTO mytable(name) SELECT name FROM mytable_tmp ORDER BY id;
DROP TABLE mytable_tmp;