[Resolved] for loop problem

[webmasternovis]

Hi all,

I'm having trouble with a for loop. It is outputting everything I want until the last result, where it doesn't output anything apart from one thing.

I think the problem is that I'm using two databases, and on the last result, only the things in one database are being outputted.

Here is my code:

for ($z=0; $z < mysql_num_rows($query); $z++)
{
// Select second database
mysql_select_db($dbname2, $connect);
$author = mysql_query("SELECT * FROM users WHERE id='$row3[author]'");

// Select normal database

mysql_select_db($dbname, $connect);
$authorrow = mysql_fetch_assoc($author);
$row3 = mysql_fetch_assoc($poemquery);

// Adjust time to correct format
$time = explode("-", $row3['date']);

echo "<a href='http://www.url.com/cat/" . $row3['id'] . "'>" . $row3['title'] . "</a><br>";
echo "By " . $authorrow['username'] . "<br>";
echo "Date added: ". $time[2] . "-" . $time[1] . "-" . $time[0] . "<br>";
}

Anyone know what the problem maybe?

Thanks,
Mike

[tsinka]

Hi,

I think the code messes up the result resources. Please post the complete code that deals with the SQL queries.

Thomas

[chyan]

maybe that happen because your for loop stopped before its equal with
your mysql_num_rows
try add equal sign after your "<"

for ($z=0; $z <= mysql_num_rows($query); $z++) {

[webmasternovis]

Hi,

Thanks for the replies. Unfortunately it didn't work adding a equals sign.

The code before the code loop is:

$var_array = explode("/",$REQUEST_URI); 
$var = $var_array[2];

$subcats = mysql_query("SELECT * FROM table WHERE urlname='$var'");
$row = mysql_fetch_assoc($subcats);

$maincats = mysql_query("SELECT * FROM table GROUP BY main");
$row2 = mysql_fetch_assoc($maincats);

if (!$var_array[3] == "")
	{
$get = "SELECT * FROM table WHERE main='$row[main]' AND sub='" . takedash($var_array[3]) ."'";
$pquery = mysql_query($get);
$row3 = mysql_fetch_assoc($pquery);

//for loop begins

Anyone know whats wrong?

Thanks a lot,
Mike 🙂

[Weedpacket]

This line looks dodgy:

if (!$var_array[3] == "") 

logical negation has a higher precedence than testing for equality;

Assume: $var_array[3]='foo'
(!$var_array[3] == "")
(!'foo' == "")
(!true == "") // type cast
(false == "") // precedence
(false == false) // type cast
true

The only way the test can fail is if $var_array[3] was empty to begin with

Assume: $var_array[3]=""
(!$var_array[3] == "")
(!"" == "")
(!false == "") // type cast
(true == "") // precedence
(true == false) // type cast
false

I'm pretty sure you want to check that $var_array[3] is not equal to "". That's

if($var_array[3] != "")

[webmasternovis]

I've changed that now, thanks 🙂

I've still got my original problem though, with the last data from the for loop only containing that from "second database".

Anyone know what's wrong?

Thanks,
Mike

[Weedpacket]

If I'm reading the comment at the of your second posted block of code right, it's immediately followed by the code in the first block, yes?

$var_array = explode("/",$REQUEST_URI); 
$var = $var_array[2];

$subcats = mysql_query("SELECT * FROM table WHERE urlname='$var'");
$row = mysql_fetch_assoc($subcats);

$maincats = mysql_query("SELECT * FROM table GROUP BY main");
$row2 = mysql_fetch_assoc($maincats);

if ($var_array[3] != "")
    {
$get = "SELECT * FROM table WHERE main='$row[main]' AND sub='" . takedash($var_array[3]) ."'";
$pquery = mysql_query($get);
$row3 = mysql_fetch_assoc($pquery);
for ($z=0; $z < mysql_num_rows($query); $z++)
{
// Select second database
mysql_select_db($dbname2, $connect);
$author = mysql_query("SELECT * FROM users WHERE id='$row3[author]'");

// Select normal database

mysql_select_db($dbname, $connect);
$authorrow = mysql_fetch_assoc($author);
$row3 = mysql_fetch_assoc($poemquery);

// Adjust time to correct format
$time = explode("-", $row3['date']);

echo "<a href='http://www.url.com/cat/" . $row3['id'] . "'>" . $row3['title'] . "</a><br>";
echo "By " . $authorrow['username'] . "<br>";
echo "Date added: ". $time[2] . "-" . $time[1] . "-" . $time[0] . "<br>"; 

If that is the case, the data you put into $row3 from the first database is never used before it gets destroyed by the data you're putting into the variable from the second database.

My preferred method would be to put all the results from both databases into a single array, and then after that go through the array to list its contents.

$results = array();
if($var_result[3]!='')
{
...$results[] = mysql_fetch_assoc(...);
for(...)
{
....$results[] = mysql_fetch_assoc(...);
}
foreach($results as $result)
{
  format time and do echoes (using $result instead of $row3)
}

[webmasternovis]

Aha 🙂

Thanks a lot Weedpacket, it worked what you said, I was simply overwriting $row3.

Thanks again mate 🙂

Mike