MySQL database self-increment ID re-ordered from 1 two methods

MySQL default self-increment ID is starting from 1, but when we have inserted a table or deleted ID by using delete, the ID will not start from 1.

When using MySQL, there is usually a self-increment ID field in the table, but when we want to empty the data in the table and re-add the data, we want the ID to be counted back from 1, in the following two ways:

The usual way to set the self-increment field:
Add when creating a table:

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

After creating the table, add:

ALTER TABLE table1 Add ID int auto_increment primary key self-increment 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 first;

Method Two:

ALTER TABLE TableName auto_increment=0

MySQL database self-increment ID re-ordered from 1 two methods