Two ways to sort the MySQL database self-increasing ID from 1

When using MySQL, there is usually a self increasing ID field in the table, but when we want to empty the data in the table to add data again, we want the ID to start counting back from 1, in the following two ways:

The usual way to set up a self-add field:
Add when creating a table:

CREATE TABLE table1 (ID int auto_increment PRIMARY key,...)

Add after creating a table:

ALTER TABLE table1 Add ID int auto_increment primary key self-add field, be sure to set to primary key.

Example

ALTER TABLE tablename drop column ID;
ALTER TABLE tablename Add ID mediumint (8) NOT null primary key auto_increment A;

Method Two:

ALTER TABLE TableName auto_increment=0