while staement inside another - php

Question

.I have the following code. I am wondering why does my "echo '<font color="#FF0000">'.$update_date2.'</font><br><br>'.$status.'<br>';" does not show on the screen?
.is it okay to use while statement inside another while statement? as shown in my code below.
<?php
$getquery = mysql_query("SELECT * FROM it_task ORDER BY task_id DESC");
while ($rows = mysql_fetch_array($getquery))
{
$id= $rows['task_id'];
$date=$rows['date'];
$update_date = $rows['update_date'];
$project=$rows['project'];
$topic=$rows['topic'];
$instby=$rows['instby'];
$inst=$rows['inst'];
$dline=$rows['dline'];
$ocome=$rows['ocome'];
$comm=$rows['comm'];
$fin=$rows['fin'];
echo "<div id=\"container\">";
echo "<table>";
echo "<tr>";
echo "<div id=\"conid\">$id</div>";
echo "<div id=\"condate\">$date</div>";
echo "<div id=\"conproject\">$project</div>";
echo "<div id=\"contask\">$topic</div>";
echo "<div id=\"conselect\">$instby</div>";
echo "<div id=\"conselect1\">$inst</div>";
echo "<div id=\"condline\">$dline</div>";
echo "<div id=\"conocome\">";
$updatesquery = "SELECT * FROM it_task_update WHERE update_id=$id";
while($rows1 = mysql_fetch_array($updatesquery));
{
$update_date2 = $rows1['update_date'];
$status = $rows1['ocome'];
$update_id = $rows1['update_id'];
echo '<font color="#FF0000">'.$update_date2.'</font><br><br>'.$status.'<br>';
}
echo "</div>";
echo "<div id=\"concomm\">$comm</div>";
echo "<div id=\"confin\">$fin</div>";
echo "</tr>";
echo "</table>";
echo "</div>";
}
?>
.where have i done wrong in this set of codes. can anyone guide me pls. TIA! More power! :)

Answer 1

$updatesquery = "SELECT * FROM it_task_update WHERE update_id=$id";
<---dude, where's my query?
while($rows1 = mysql_fetch_assoc($updatesquery));
You're not actually executing the query. You're trying to perform a fetch on a string, which is an error condition in MySQL, causing the fetch call to return FALSE, which makes the while() loop terminate immediately..
in other words, you're missing a call to mysql_query() in between those lines.
on another note, if the inner loop is going to be executed "many" times, you should look at rewiting both queries as a single one with a JOIN clause. It's almost always after to do a single large query then run multiple smaller ones.

Answer 2

Do you have any results from SELECT * FROM it_task_update WHERE update_id = $id?
Try doing
print_r($rows1); before line $update_date2 = $rows1['update_date'];
and view the results.

Answer 3

You have a semicolon after the inner while
while($rows1 = mysql_fetch_assoc($updatesquery));
{
// stuff
}
should be
while($rows1 = mysql_fetch_assoc($updatesquery))
{
// stuff
}

Answer 4

You're trying to retrieve results inside processing your query from a query you never execute. Notice that you called mysql_query before you started looping through your results. Then notice you tried to start fetching results from a query you never executed inside your inner while loop.

Answer 5

Yes, it is OK, to have a while or another type of loop inside another one, because it depends on your business logic. You have forgotten to execute the second query before the while loop, though. It would be better if you did this with an INNER JOIN or something so you don't waste the resources.
Also, I would suggest you not to print out the DOM elements with echo, but have them there like this <div id="username">Username: <?php echo $username; ?></div>. However, even in your case there is place for keeping your code clean. Here is my suggestion:
<?php
$getquery = mysql_query("SELECT * FROM it_task ORDER BY task_id DESC");
while ($rows = mysql_fetch_array($getquery))
{
$id= $rows['task_id'];
$date=$rows['date'];
$update_date = $rows['update_date'];
$project=$rows['project'];
$topic=$rows['topic'];
$instby=$rows['instby'];
$inst=$rows['inst'];
$dline=$rows['dline'];
$ocome=$rows['ocome'];
$comm=$rows['comm'];
$fin=$rows['fin'];
echo '<div id="container\">'.
'<table>'.
'<tr>'.
"<div id=\"conid\">$id</div>".
"<div id=\"condate\">$date</div>".
"<div id=\"conproject\">$project</div>".
"<div id=\"contask\">$topic</div>".
"<div id=\"conselect\">$instby</div>".
"<div id=\"conselect1\">$inst</div>".
"<div id=\"condline\">$dline</div>".
"<div id=\"conocome\">";
$updatesquery = "SELECT * FROM it_task_update WHERE update_id=$id";
// you need to execute the query
$updatesresult = mysql_query($updatesquery);
while($rows1 = mysql_fetch_assoc($updatesresult)) // <-- no semicolon here
{
$update_date2 = $rows1['update_date'];
$status = $rows1['ocome'];
$update_id = $rows1['update_id'];
echo '<font color="#FF0000">'.$update_date2.'</font><br><br>'.$status.'<br>';
}
echo '</div>'.
"<div id=\"concomm\">$comm</div>".
"<div id=\"confin\">$fin</div>".
'</tr>'.
'</table>'.
'</div>';
}
?>
Update
Your inner while statements should not be terminated with a semicolon at the logic point. Please check the code above to see where I have placed the comment for you.