mysqli_fetch_array reading result as null? - php

Question

Any idea why this is showing a result of null? I'm guessing it has to do with where I put $link before I did the query, but it has to be done that way, correct?
function getcatposts($cat_id) {
$qc = #mysqli_query($link, "SELECT * FROM topics WHERE topic_cat='$cat_id'");
while($row = mysqli_fetch_array($qc)) {
$topic_title=$row['topic_subject'];
$topic_id=$row['topic_id'];
}
$qc2 = #mysqli_query($link, "SELECT * FROM categories WHERE cat_id='$cat_id'");
while($row2 = mysqli_fetch_array($qc2)) {
$cat_name=$row2['cat_name'];
}
Updated code:
function getcatposts($cat_id) {
$link = mysqli_connect("localhost", "lunar_lunar", "", "lunar_users");
$qc = mysqli_query($link, "SELECT * FROM topics WHERE topic_cat='$cat_id'");
while($row = mysqli_fetch_array($qc)) {
$topic_title=$row['topic_subject'];
$topic_id=$row['topic_id'];
}
$qc2 = mysqli_query($link, "SELECT * FROM categories WHERE cat_id='$cat_id'");
while($row2 = mysqli_fetch_array($qc2)) {
$cat_name=$row2['cat_name'];
}
echo $cat_name;
echo '<br />';
echo $topic_title;
echo '<br />';
echo $topic_id;
}
New issue is that its displaying like this:
http://gyazo.com/43e8a91b9e0cf4f5e413536907891dcf.png
When the DB looks like this:
http://gyazo.com/1ead8bd0f150838dae3ee4a476419679.png
It should be displaying all three of them and this is a function meaning it will keep redoing all the code until it can't query anymore data. Any ideas?

Answer 1

The problem here is that you're trying to echo the values outside your loop. The variables inside the loop will get overwritten on each iteration and at the end of looping, the variable will hold the value of the last iteration.
If you want to display all the values, move the echo statement inside your loop, like so:
while($row = mysqli_fetch_array($qc))
{
$topic_title = $row['topic_subject'];
$topic_id = $row['topic_id'];
echo $topic_title.'<br/>';
echo $topic_id.'<br/>';
}
$qc2 = mysqli_query($link, "SELECT * FROM categories WHERE cat_id='$cat_id'");
while($row2 = mysqli_fetch_array($qc2))
{
$cat_name = $row2['cat_name'];
echo $cat_name.'<br/>';
}
If you care about the order, you could store the titles, ids and cat_names in arrays like so:
while($row = mysqli_fetch_array($qc))
{
$topic_title[] =$row['topic_subject'];
$topic_id[] = $row['topic_id'];
}
$qc2 = mysqli_query($link, "SELECT * FROM categories WHERE cat_id='$cat_id'");
while($row2 = mysqli_fetch_array($qc2))
{
$cat_name[] =$row2['cat_name'];
}
And then loop through them:
for ($i=0; $i < count($topic_id); $i++) {
if( isset($topic_id[$i], $topic_title[$i], $cat_name[$i]) )
{
echo $cat_name[$i].'<br/>';
echo $topic_title[$i].'<br/>';
echo $topic_id[$i].'<br/>';
}
}

Answer 2

Your function displays only one result because your echo is outside the while loop...
Put the Echo statements inside the loop, or you will print only the last result!
while($row = mysqli_fetch_array($qc)) {
$topic_title=$row['topic_subject'];
$topic_id=$row['topic_id'];
echo $topic_title;
echo '<br />';
echo $topic_id;
}
$qc2 = mysqli_query($link, "SELECT * FROM categories WHERE cat_id='$cat_id'");
while($row2 = mysqli_fetch_array($qc2)) {
$cat_name=$row2['cat_name'];
echo $cat_name;
echo '<br />';
}