如果满足列条件，则随机选择行

My ads_man table has the following structure;

I want to select rows randomly from this table if column "rotate" is 1, otherwise if rotate = 0 then it shouldn't select these rows randomly. I've tried this;

$query = $db->query("
    SELECT type,place,code
    FROM ads_man
    WHERE approved = '1' AND fid = '{$fid}' AND place = '{$zone}'
    ORDER BY RAND()
    LIMIT 3");

It selects the rows randomly but issue is I'm unable to find a quick way to select these rows rather to use another query to find all those rows having rotate = 1 and then use ORDER BY RAND() in the query mentioned above.

Please help!

Try this;

$r_q = $db->query("SELECT rotate FROM ads_man");
$r = $db->fetch_array($r_q);
if($r['rotate'] == "1")
{
    $rotate = 'rotate = "0" OR rotate = "1" AND';
    $order_by = 'ORDER BY RAND()';
}
else
{
    $rotate = 'rotate = "0" AND';
    $order_by = 'ORDER BY dateline DESC';
}

$query = $db->query("
    SELECT type,place,code
    FROM ads_man
    WHERE {$rotate} approved = '1' AND fid = '{$fid}' AND place = '{$zone}'
    {$order_by}
    LIMIT 3");

$query = $db->query("
    SELECT type,place,code
    FROM ads_man
    WHERE rotate='1' AND approved = '1' AND fid = '{$fid}' AND place = '{$zone}'
    ORDER BY RAND()
    LIMIT 3");

I think it is better to add a random number column by ALTER statement in given table. That will save lot of time.

There are several ways to do this:

It's not very clear what you need but, if you need 3 rows with rotate = 1 selected randomly and then others (for example 7) with rotate = 0 then you can do it with an UNION

(SELECT type,place,code
    FROM ads_man
    WHERE rotate = 1 AND approved = '1' AND fid = '{$fid}' AND place = '{$zone}'
    ORDER BY RAND()
    LIMIT 3)
UNION
(SELECT type,place,code
    FROM ads_man
    WHERE rotate = 0 AND approved = '1' AND fid = '{$fid}' AND place = '{$zone}'
    LIMIT 7)

Is this what you need? Let me know if not

Edited: Forgot parenthesis