why can't it populate the whole list of products

Question

I don't know what is wrong with my code. supposingly, it should be populating all the items that I have in my database(id) however, it just tell me how many item I have in my database instead of listing out all the ids of products that I have in my database

Can someone help to pointed out my mistakes? I'm following a tutorial on youtube on making the shopping cart.

<?php
$product_list = "";
$sql = mysql_query("SELECT * FROM supermarket");
$productCount = mysql_num_rows($sql);//count output amount
if($productCount > 0){
    while($row = mysql_fetch_array($sql)){
        $id = $row["id"];
        $product_list = "$id<br>";
    }
}
else{
    $product_list = "You have no products listed in your store yet";
}
?>

You are erasing $product_list content every time you pass inside the loop. The only thing stocked inside $product_list is the last id in your query. — GeoffreyB, Jan 16 '14 at 11:12
you overwrite your $product_list every sequence of your loop. store in in a array: `$product_list[] = "$id"` — Gert B., Jan 16 '14 at 11:12

score 4 · Answer 1 · edited May 25 '19 at 14:01

4

You're overwriting your $product_list variable. Instead you need to take all your id in array variable,

$product_list = array();
if($productCount > 0){
    while($row = mysql_fetch_array($sql)){
        $id = $row["id"];
        $product_list[] = $id;
    }
}
print_r($product_list);

Note: Please, don't use mysql_* functions in new code. They are no longer maintained and are officially deprecated. See the red box? Learn about prepared statements instead, and use PDO, or MySQLi - this article will help you decide which. If you choose PDO, here is a good tutorial.

edited May 25 '19 at 14:01

Zoe

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answered Jan 16 '14 at 11:10

Rikesh

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This is not a complete code. You need to add this after your line `$productCount = mysql_num_rows($sql);`. Just replace this with your current `if condition`. – Rikesh Jan 16 '14 at 12:26
What is the column name for `item id` ? – Rikesh Jan 16 '14 at 12:31

score 1 · Accepted Answer · answered Jan 16 '14 at 11:14

Every time round your while loop, you're overwriting the previous contents of $product_list. You presumably want to concatenate instead using the .= operator, like this:

while($row = mysql_fetch_array($sql)){
    $id = $row["id"];
    $product_list .= "$id<br>";
}

I'm assuming here that you're outputting $product_list later (some time after the loop), e.g.:

echo $product_list;

score 0 · Answer 3 · answered Jan 16 '14 at 11:15

If you want all data from your product:

$product_list = array();
  if($productCount > 0){
  while($row = mysql_fetch_array($sql)){
    $id = $row["id"];
    $product_list[$id] = $row;
  }
}
print_r($product_list);

you have to store it in a array, you overwrite you $product_list every sequence of the while loop its not the count you get btw, its the last id fetched you get returned in your code

why can't it populate the whole list of products

3 Answers3