up vote 1 down vote favorite

I tested looping nested While statements so:

$count1 = 0;

while ($count1 < 3) {
 $count1++;
 $count2 = 0;
 echo "count1: ".$count1."<br />";

    while ($count2 < 3) {
    $count2++;
    echo "count2: ".$count2."<br />";
    }
}

This works perfectly (looping three times each) with results: 

count1: 1
 count2: 1
 count2: 2
 count2: 3
count1: 2
 count2: 1
 count2: 2
 count2: 3
count1: 3
 count2: 1
 count2: 2
 count2: 3

Then I tried the same with a loop using mysql_fetch_assoc ($ContactsInterests is a two row associative array, and $LatestNews has 50 rows) i.e.

$CI_count = 0;

while ($CI_Row = mysql_fetch_assoc($ContactsInterests)) { //loop thru interests
$CI_count++;
$LN_count = 0;
echo "CI_count: ".$CI_count."<br />";

while ($LN_Row = mysql_fetch_assoc($LatestNews)) { //loop thru news
    $LN_count++;
    echo "LN_count: ".$LN_count."<br />";

}
}

The results are:

CI_count: 1
 LN_count: 1
 LN_count: 2
 ...
 LN_count: 50
 LN_count: 51
CI_count: 2

But where it the second iteration of LN_count? I don't understand why the LN_count didn't increment a second time.

Help appreciated.

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1  
mysql_data_seek($result, 0) – chris Jun 23 '12 at 19:40
at the top add $LN_Row = array(); Then, at the end of the first while loop add reset($LN_Row); – redskins80 Jun 23 '12 at 19:41
@redskins80 the $LN_Row contains only the last value passed by mysql_fetch_assoc... so it won't fill up the $LN_Row unless you do something like this $LN_Row[] = mysql_fetch_assoc – Dexter Huinda Jun 23 '12 at 19:49
@Dexter youre right! ive deleted my answer. sry. – redskins80 Jun 23 '12 at 19:51
1  
STOP USING THE mySQL_* EXTENSIONS IMMEDIATELY. They are being deprecated. Use either PDO our the I extensions. – Brendan Jun 23 '12 at 19:51
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4 Answers

up vote 1 down vote accepted

mysql_fetch_assoc does iteration for "mysql result" type. Seeks index for each fetch. you must use mysql_data_seek to go to the first result like;

<?php

    $CI_count = 0;

    while ($CI_Row = mysql_fetch_assoc($ContactsInterests)) { //loop thru interests
        $CI_count++;
        $LN_count = 0;
        echo "CI_count: ".$CI_count."<br />";

        mysql_data_seek($LatestNews,0);
        while ($LN_Row = mysql_fetch_assoc($LatestNews)) { //loop thru news
            $LN_count++;
            echo "LN_count: ".$LN_count."<br />";

        }
    }
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Fantastic! Thanks Tufan. Works like a charm. – Jeremy Jun 23 '12 at 20:16
up vote 0 down vote

Because the results have been exhausted. You've iterated through all of them... If you wanted to loop again you're have to repopulate the $LatestNews variable.

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up vote 0 down vote

You need to reset the mysql internal pointer:

see http://php.net/mysql_data_seek

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up vote 0 down vote

mysql_fetch_assoc() takes out one by one the rows of the source, you when you will be in the second step of the first loop, you wont have any rows in the source variable.

You need to put the results of the second query in an array, then loop the array, and not using mysql_fetch_assoc.

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