Question

Here is my original query…

SELECT `id`
  FROM `properties`
 LIMIT 10, 20

The LIMIT condition is for pagination.

Now, I have to get all like before, but I need to get only a third of rows where a condition is present.

I came up with this, just throwing LIMIT 30 in before I figured out how to do (total rows matched / 3) * 2.

SELECT `id`
  FROM `properties`
 WHERE `id` NOT IN (SELECT `id` 
                      FROM `properties` 
                     WHERE `vendor` = "abc" 
                  ORDER BY RAND() 
                     LIMIT 30)
LIMIT 10, 20    

MySQL said…

1235 – This version of MySQL doesn’t yet support ‘LIMIT & IN/ALL/ANY/SOME subquery’

I guess I can’t use LIMIT in a subquery.

So this is a multi question but all related…

• Is there a workaround for LIMIT in subquery?
• Can I select a 1/3 of matched rows with MySQL?
• Do I need to turn this into 2 queries, or just select all and unset the rows not required in PHP?

Answer 1

If your version of MySQL doesn’t support that then you have 2 options:

• Upgrade. Always fun, and it’s generally best to be on the latest version.
• Break out your subquery using php. Grab the ids, then format the results into a comma separated string.