results are empty for query... why?

[squirrelly1]

I've tried using the following code to access one record in my database table...


function downloadfile($fc)
{
print "hmmm<br>";

$sql = " SELECT * FROM myTable ";
$sql .= " WHERE id=$fc ";

print "$sql<br>";

$rs = mysql_query($sql, $cid);
if (mysql_error()) { print "Database Error: $sql " . mysql_error(); }

if (mysql_num_rows() == 0)
{
print "Nothing in the recordset.<br>";
} else {
print "Something in the recordset.<br>";
}

while ($row = mysql_fetch_array($rs))
{
print "hmm";
//$fileloc = $row['fileloc'];
//print "File Location: $fileloc";
//header("Location: " . $fileloc);
}
print "After while loop.<br>";
exit(0);
}


it returns the following...

hmmm
SELECT * FROM myTable WHERE id=59
Nothing in the recordset.
After while loop.


yet when I use this exact same query directly in MySQL it returns the appropriate record!

any ideas on why this is messing up like this?

Squirrelly1

[sciguyryan]

CHange this:


$sql = " SELECT * FROM myTable ";
$sql .= " WHERE id=$fc ";


To this:

$sql = "SELECT * FROM `myTable` WHERE `id` = '$fc'";


And it should then work :)

Cheers,

RyanJ

[squirrelly1]

The SQL statement was not the problem... that's what I was trying to express when I said that I checked the SQL statement directly in MySQL... My error trap would have detected if it were the problem...

still not working with ur modification, thanks though...

Squirrelly1

[sciguyryan]

Ah, I think i have found it:


if (mysql_num_rows() == 0)


Should be:


if (mysql_num_rows($rs) == 0)


From the PHP Manual:


mysql_num_rows
(PHP 3, PHP 4 , PHP 5)

mysql_num_rows -- Get number of rows in result
Description
int mysql_num_rows ( resource result )

Retrieves the number of rows from a result set. This command is only valid for SELECT statements. To retrieve the number of rows affected by a INSERT, UPDATE, or DELETE query, use mysql_affected_rows().

Parameters


result
The result resource that is being evaluated. This result comes from a call to mysql_query().

Return Values
The number of rows in a result set on success, or FALSE on failure.



Cheers,

RyanJ

[squirrelly1]

I think I figured out the problem, but I'm not sure how to solve it...

The code I listed is inside of a function within my php script. For some reason, the function is not able to see the $cid or any of the other variables that were set outside of the function.


How can I fix this or see if it really is the problem?

squirrelly1

[Brandoe85]

They wont be able to recognize the variables, unless they are global. Take a look here variable scope (http://us2.php.net/variables.scope)

[visualAd]

I think I figured out the problem, but I'm not sure how to solve it...

The code I listed is inside of a function within my php script. For some reason, the function is not able to see the $cid or any of the other variables that were set outside of the function.


How can I fix this or see if it really is the problem?

squirrelly1
You can either use a global declaration or access it directly through the $BLOBALS array.

You should test the return type of mysql_query() to check whether the query has failed:

function downloadfile($fc)
{
global $cid;

print "hmmm<br>";

$sql = " SELECT * FROM myTable ";
$sql .= " WHERE id=$fc ";

print "$sql<br>";

if (! $rs = mysql_query($sql, $cid)) {
print "Database Error: $sql " . mysql_error();
return;
}

if (mysql_num_rows($rs) == 0)
{
print "Nothing in the recordset.<br>";
} else {
print "Something in the recordset.<br>";
}

while ($row = mysql_fetch_array($rs))
{
print "hmm";
//$fileloc = $row['fileloc'];
//print "File Location: $fileloc";
//header("Location: " . $fileloc);
}
print "After while loop.<br>";
exit(0);
}