Question

I have a MySQL table that contains the columns id, created_date, and name, where id is the auto-incremented primary key (starting at 1) and created_date is the date the row was created (just an example).

There are 50 rows in this table since the launch of this application. Suppose I have 100 old records (considering the created_date values) that I want to import into this table.

Is there a simple way to shift the id values of the current records to 101-150, so I can import the old records with id values of 1-100? Is this even advisable?

If I had to do it over again, I would’ve adjusted up the auto-increment of the id column (primary key) before launching the application to accommodate the records I intended to import.

Answer 1

You could renumber them with an UPDATE command:

UPDATE table SET id = id + 100;

Or import them into a new table which has the AUTO_INCREMENT value pre-set:

 CREATE TABLE `table` (
  `id` int(10) unsigned NOT NULL auto_increment,
  PRIMARY KEY  (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=101;

You’ll need to take care to ensure that you maintain referential integrity – if other tables reference this table, then you’ll need to make sure that they are updated too.