using nested queries in nested foreach loops

Question

Okay, after pounding my head against the wall for about 2 hours, I need help. I have a query that pulls "comments" based on a users "followers". The followers have a unique id, and lets say just for ease of use, their id's are 4 and 5. The query returns all followers, so there could be way more than just two rows. That query creates a foreach that I want to say for each "follower" execute this query. Then, that query needs to create a fetch_assoc() so that the data can be recalled later on down the page. The way I have the code right now, it only shows postings from follower 4, and not 5. I have tried using counters to append variable names so that they wont get overwritten each time, but it doesnt help. Thanks a lot!

$sqlb ="SELECT myfriend_ID FROM friends WHERE my_id = '$myuid'";
$resultb = mysql_query($sqlb,$db);
$numa = mysql_num_rows($resultb);
if($numa)
{
    while(($follower = mysql_fetch_assoc($resultb))) {
        $followers[] = $follower;
    }
}
$i=0;
foreach($followers as $follower)
{
    $i++;
    $fnub = $follower['myfollower_ID'];//this will print 4 and 5
    $fnum = $fnub;

    $sql = "SELECT * FROM usr, feed, course WHERE usr.usr_id = '$fnum' AND 
             feed.usr_id = '$fnum' AND course.usr_id = '$fnum' ORDER BY Feed_ID desc";
    $result = mysql_query($sql,$db);
    $num.$fnum = mysql_num_rows($result);
    if($num.$fnum)
    {
        while(($feed = mysql_fetch_assoc($result))) {
            $feeds[] = $feed;
        }
        foreach($feeds as $feed)
        {
            echo $feed['comment'];
        }
    }
}

You should really clean you code. Useless looping, assignments are there. You are selecting myfriend_ID in sql query but using myfollower_ID. and probably $follower['myfollower_ID'] this is coming from anywhere else. — Gaurav
– Gaurav, Commented Apr 2, 2011 at 6:07
right, I intend to as soon as I figure out how to make it work, the $i's that you see are leftover from some attempts at appending $result and $sql as I tried to do with $fnum and $num — Ryan
– Ryan, Commented Apr 2, 2011 at 6:09
When posting something to stackoverflow, it's nice etiquette to reduce the code to a minimum so people don't have to waste time eliminating all the garbage. $i for example is completely irrelevant here. — EboMike
– EboMike, Commented Apr 2, 2011 at 6:23

Gaurav · Accepted Answer · 2011-04-02 06:13:14Z

1

$sqlb ="SELECT myfriend_ID FROM friends WHERE my_id = '$myuid'";
$resultb = mysql_query($sqlb,$db);
$follower = array();

if(mysql_num_rows($resultb))
{
   while(($follower = mysql_fetch_assoc($resultb))) {
      $fnum = $follower['myfriend_ID'];//what is the column name
      $sql = "SELECT * FROM usr, feed, course WHERE usr.usr_id = '$fnum' AND feed.usr_id = '$fnum' AND course.usr_id = '$fnum' ORDER BY Feed_ID desc";
      $result = mysql_query($sql,$db);
      if( mysql_num_rows($result))
      {
         while(($feed = mysql_fetch_assoc($result))) {
           echo $feed['comment'];
       }
    }
}

And you must combine these two queries into single. But I am not too good in SQL. Probably some one other can help.

answered Apr 2, 2011 at 6:13

Gaurav

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Comments

linus72982 · Accepted Answer · 2011-04-02 06:15:47Z

0

You assign $i, then you increment $i within the foreach, but you never use $i for anything else, I'm not sure what that counter is supposed to do. I'm unsure of why you assign a second variable to the value of $fnub, why not just use $fnub each time? Later you use (what we can only assume is) an empty $num variable and prepend $fnum with it - I'm not sure why - or even why you have to assign anything to the num rows, just use the function within the if as that looks to be the only instance you are using $num.$fnum.

You can take your last foreach out completely and move the content of that loop into the while before it as they both are iterating over the same data, just assign the values, then echo $feed['comment'] out right there, then it will move the pointer and have the next value ready for you by itself.

answered Apr 2, 2011 at 6:15

linus72982

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2 Comments

Ryan Over a year ago

yeah, its sloppy, but the $i was supposed to be for appending other variables, it didnt work, so I took it out, except I forgot to prune some things like $i and $fnum, they were all mostly just experimental

linus72982 Over a year ago

The point I was trying to get at was that if you clean it up it might be much easier to see where the issue lies. Right now it is very hard to read as you name the arguments of foreach the same things with an s at the end, and then use those names again later, etc. Makes it super hard to remember what everything was and where everything is supposed to go, etc.

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