Select less than an id

If I have a 1,000 items in a table and I want to get a random number ..

$randnumber = '700';

How could I select items:

700,699,698,697,696

from the table with 1 query that isn't where id='', is this possible? I was trying less than but it gets 1,2,3,4,5..

 

SELECT * FROM table ORDER BY RAND() LIMIT 5

Code (markup):

Like that?

 

Yes, but the table has over 100,000 rows so I'm trying to do it in a way that won't put as high a load in the processor?

 

PHP, then.

<?php
$row_count = mysql_num_rows(mysql_query("SELECT * FROM table")); //unless you want to hard-code the number
$random_row_number = rand(1, $row_count);
$random_row = mysql_fetch_assoc(mysql_query("SELECT * FROM table WHERE id=$random_row_number"));
?>

Code (markup):

Loop that or pre-fill an array with as many rows as you want to retrieve. That's the simplest solution I can come up with quickly.

 

SELECT * FROM table

Code (markup):

This is going to create a lot of data flowing, all 100,000 rows being returned every time.

Is your ID column a sequential number? If it is then

SELECT Max(RowID) FROM TableName;

Code (markup):

would be much better. You can then use the code to do the randomisation and then select those X rows. Alternative create a stored procedure that does the same.

 

Thanks for that. I was going to write SELECT id but wasn't sure of the field names. I should have mentioned that because that's potentially a LOT of data haha.