php and mysql fill empty values as empty 's

Question

I'm trying to compare products and I'm already finished. I just have a problem that my product features are not under the right product names because I need to fill the gaps between with empty <td></td>.

Here is my code from the function that fills the values.

function datatable($id)
{
 $conn = connection();
 $productPost = $_POST["product"];

 $sqlSpecTitle = "Select title as title from product where uid = '$id'";
 $resultTitle = mysqli_query($conn, sqlSpecTitle) or die("database error:" . mysqli_error($conn));
 
 foreach ($productPost as $product)
 {
   $sqlSpecValue = "Select productname, title, value from text join product on uid = uid join feature on uid = uid where productname = '$product" and uid = '$id';
   $resultValue = mysqli_query($conn, $sqlSpecValue or die("database error:" . mysqli_error($conn));

  if(mysqli_num_row($resultValue) > 0
  {
    while($row = mysqli_fetch_assoc($resultTitle))
    {
      echo "<td>" . $row['title'] . "<td>";
    }
    while ($row = mysqli_fetch_assoc($resultValue))
    {
     if($row['value'] == null)
     {
      echo "<td>" . "empty" . "<td>";
     }
     else
     {
       echo "<td> . $row['value'] . "</td>";
     }
    }
   }
  }
 }

The productnames are getting filled in another function that is as much the same.

function headerTable()
    {
        $conn = connection();
        $productPost = $_POST["product"];

        foreach ($productPost as $product) {
            $sqlSpecValue = "SELECT productname, title, value from text
            join product on uid = uid
            join feature on uid = uid
            where productname = '$product';
            $resultValue = mysqli_query($conn, $sqlSpecValue) or die("database error:" . mysqli_error($conn));


            $row = mysqli_fetch_assoc($resultValue);
            echo "<td id='product'>" . $row['productname'] . "</td>";
        }
    }

`$foreach ($productPost as product)` Is that your actual code with the `$` before `foreach` but missing from `product`? — brombeer, Oct 20 '21 at 07:39
Ah sry. I did a pasting mistake there. I changed it. Thx for your reply. — skeler137, Oct 20 '21 at 07:44
**Warning:** You are wide open to [SQL Injections](https://php.net/manual/en/security.database.sql-injection.php) and should use parameterized **prepared statements** instead of manually building your queries. They are provided by [PDO](https://php.net/manual/pdo.prepared-statements.php) or by [MySQLi](https://php.net/manual/mysqli.quickstart.prepared-statements.php). Never trust any kind of input! Even when your queries are executed only by trusted users, [you are still in risk of corrupting your data](http://bobby-tables.com/). [Escaping is not enough!](https://stackoverflow.com/q/5741187) — Dharman, Oct 20 '21 at 09:35
It is a very bad idea to use `die(mysqli_error($conn));` in your code, because it could potentially leak sensitive information. See this post for more explanation: [mysqli or die, does it have to die?](https://stackoverflow.com/a/15320411/1839439) — Dharman, Oct 20 '21 at 09:35

score 0 · Answer 1 · answered Oct 20 '21 at 07:54

0

You make a "join" over between your tables, so you only get data if you have something in "text" table. Just switch to "right join" and it should work.

answered Oct 20 '21 at 07:54

Nalar

1

I get all the data I need. I just need to fill empty 's if there is no value for the specified productname. – skeler137 Oct 20 '21 at 08:09
Yep, but by using right join, you'll get null value for product/feature when text is not filled, instead of not having data. With that, your "if" block should work. – Nalar Oct 20 '21 at 08:36
I put the data into an array and investigated it I can't see any "null" values in there. The problem here is that $row['value'] always gets the whole data of my result. – skeler137 Oct 20 '21 at 09:05

php and mysql fill empty values as empty 's

1 Answers1