Question

I need to delete all rows from a table but when I add a new row, I want the primary key ID, which has an auto increment, to start again from 0 respectively from 1.

Answer 1

Do not delete, use truncate:

Truncate table XXX

The table handler does not remember the last used AUTO_INCREMENT value, but starts counting from the beginning. This is true even for MyISAM and InnoDB, which normally do not reuse sequence values.

Source.