Nested while loop doesn't loop as expected

Question

I has problem looping the second while Loop.It will only loop once.So I can only get the value for the first row for the second loop. Please help me to figure this out, I am a beginner.

<ul id="navbar">

     <?php
     $rel = "SELECT * FROM table1 ORDER BY category";
     $sql=$db->query($rel); 
     while($row = $sql -> fetch_array()){
     ?>

     <li><a href="category.php?id=<?php echo $row['category_id'];?>"><?php echo $row['category'];?></a> 

        <ul>

            <?php
            $sel = "SELECT * FROM table2 WHERE category_id=".$row['category_id']." ORDER BY subcategory ASC";
            $sql=$db->query($sel);  
            while($row1 = $sql -> fetch_array()){
            ?>

            <li><a href="subcategory.php?id=<?php echo $row1['subcategory_id'];?>"><?php echo $row1['subcategory'];?></a></li>

            <?php }?>

        </ul>
    </li>

    <?php }?>

</ul>

Kaii · Accepted Answer · 2012-04-24 06:55:30Z

3

You are overwriting $sql for the inner loop, invalidating it for the outer one. Use another variable name for the SQL result identifier in the second query.

edited Apr 24, 2012 at 6:55

Kaii

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answered Apr 24, 2012 at 6:53

Ed Heal

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Comments

Andreas Eriksson · Accepted Answer · 2012-04-24 06:54:13Z

2

Well, you are keeping the results of the first query in the variable $sql

$sql=$db->query($rel);

But then, before the second loop, you overwrite that variable.

$sql=$db->query($sel);

Try declaring a new variable for the second use. Say, $sql2.

answered Apr 24, 2012 at 6:54

Andreas Eriksson

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1 Comment

Lionel Aaron D'souza Over a year ago

Thank you for having a look at my codes and helping me out...that was really helpful

Radu Murzea · Accepted Answer · 2012-04-24 06:55:22Z

1

The reason for this is that you use the variable $sql for both queries. Rename the second one to $sql2 for example.

Also, avoid using so many <?php ?> tags.

answered Apr 24, 2012 at 6:55

Radu Murzea

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1 Comment

Lionel Aaron D'souza Over a year ago

Thank you, I'll make a note of that...this was really helpful. Thank you for having a look at my codes.

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