Problem with nested SQL

I have a problem with nested select in MySQL.

This one works, but I need to get two of them.

Example:

SELECT `a`.`title` , `a`.`askprice` , `a`.`picture` 
, `a`.`description` , `a`.`userid` , `a`.`id`
FROM (
`mm_ads_fields_values` AS afv
)
LEFT JOIN `mm_ads` AS a ON `a`.`id` = `afv`.`aid`
WHERE `afv`.`value` = '38'
AND `a`.`category` = '227'
AND `a`.`status` =1
AND a.id
IN (
    SELECT a.id
    FROM mm_ads AS a
    LEFT JOIN mm_ads_fields_values AS afv ON afv.aid = a.id
    WHERE afv.value = '2913'
)
ORDER BY `id` DESC
LIMIT 20 

This one works. But I need SQL statement like this one:

SELECT `a`.`title` , `a`.`askprice` , `a`.`picture` 
, `a`.`description` , `a`.`userid` , `a`.`id`
FROM (
`mm_ads_fields_values` AS afv
)
LEFT JOIN `mm_ads` AS a ON `a`.`id` = `afv`.`aid`
WHERE `afv`.`value` = '38'
AND `a`.`category` = '227'
AND `a`.`status` =1
AND a.id
IN (
   SELECT a.id
   FROM mm_ads AS a
   LEFT JOIN mm_ads_fields_values AS afv ON afv.aid = a.id
   WHERE afv.value = '2913'
)
AND a.id
IN (
    SELECT a.id
    FROM mm_ads AS a
    LEFT JOIN mm_ads_fields_values AS afv ON afv.aid = a.id
    WHERE afv.value = '51'
)
ORDER BY `id` DESC
LIMIT 20 

And this one, last one, won't wor开发者_如何学Pythonk. Its loading, loading and never nothing happen..

What am I doing wrong?

Regards, Mario

Sorry for my bad English..

Glib answer: shouldn't the second IN statement use OR instead of AND? (edit: and use correct operator precedence.)

...
AND 
( a.id
  IN (
     SELECT a.id
     FROM mm_ads AS a
     LEFT JOIN mm_ads_fields_values AS afv ON afv.aid = a.id
     WHERE afv.value = '2913'
  )
  OR a.id
  IN (
      SELECT a.id
      FROM mm_ads AS a
      LEFT JOIN mm_ads_fields_values AS afv ON afv.aid = a.id
      WHERE afv.value = '51'
  )
)
...