Selecting the oldest 20 number of records

[PHP5000]

Hi

Any idea what is SQL command to select the oldest 20 records in a Mysql table?

I know it can be done with reading the number of records and recording the oldest id and newest id and setting a range, but I am trying to find a more efficient and quicker way to do this.  (In a single SQL command).

Thanks in advance

Edited November 26 by PHP5000

[Barand]

select <whatever>
from <tablename>
order by date_created
limit 20

 

[PHP5000]

Brand this would only work if I had a column saving the dates (date_created), which I do not. Also supposing I wanted to delete the records.

Any idea how to adopt this notion to DELETE, specially without date ?

Thanks in advance

 

Edited November 27 by PHP5000

[mac_gyver]

you would ORDER BY the id (autoincrement primary index) column instead.

a DELETE query has the same ORDER BY and LIMIT terms as a SELECT query.

[PHP5000]

Many thanks to both of you.  It worked like a charm.

[Barand]

7 hours ago, mac_gyver said:

you would ORDER BY the id (autoincrement primary index) column instead.

But only if you can guarantee that the oldest records are always added first. If relative age is important why would you not store the date added?

Having a date also has the advantage that you can have the option to
 

DELETE FROM tablename
WHERE datecol < CURDATE() - INTERVAL ? DAY

so you can delete all those over N days old