CODEWITHSUNDEEP
php
phunder
phunder

Reputation: 1713

Database not updating when using PHP var's

I am doing some simple PHP and SQL for the first time in quite a while, but for some reason am not getting it to work. When I provide fixed values it all works fine, but as soon as I replace them with variables my code fails. I have checked and it seems that the variables have proper values in them:

This works:

<?php
    $con=mysqli_connect("localhost","xxx","xxx","xxx");

    if (mysqli_connect_errno())
      {
      echo "Failed to connect to MySQL: " . mysqli_connect_error();
      }

     if(isset($_GET['id'])){
        $ID = $_GET['id'];
        $newStock = $_GET['stockcount'] - 1;
        mysqli_query($con,'UPDATE products SET stockcount = "3" WHERE id = "1"');   
     }
    else
        echo "Invalid item";


    mysqli_close($con);

    header('Location: browse.php');
?>

But not this:

<?php
    $con=mysqli_connect("localhost","xxx","xxx","xxx");

    if (mysqli_connect_errno())
      {
      echo "Failed to connect to MySQL: " . mysqli_connect_error();
      }

     if(isset($_GET['id'])){
        $ID = $_GET['id'];
        $newStock = $_GET['stockcount'] - 1;
        mysqli_query($con,'UPDATE products SET stockcount = "'+$newStock+'" WHERE id = "'+$ID+'"'); 
     }
    else
        echo "Invalid item";


    mysqli_close($con);

    header('Location: browse.php');
?>

Do I need to do something with the variables, or am I doing something else wrong? As always, any advice would be greatly appreciated :)

Upvotes: 0

Views: 36

Answers (2)

Casey Dwayne
Casey Dwayne

Reputation: 2169

mysqli_query($con,'UPDATE products SET stockcount = "'.$newStock.'" WHERE id = "'.$ID.'"');

This isn't javascript. Connotate with . not +. Better yet, just pass it in string by using double-quotes!

mysqli_query($con,"UPDATE products SET stockcount = '$newStock' WHERE id = '$ID'");

Upvotes: 0

Abhik Chakraborty
Abhik Chakraborty

Reputation: 44844

" + " is not used for concatenate string in PHP as you did

 mysqli_query($con,'UPDATE products SET stockcount = "'+$newStock+'" WHERE id = "'+$ID+'"');

it should be as

 mysqli_query($con,'UPDATE products SET stockcount = "'.$newStock.'" WHERE id = "'.$ID.'"');

Upvotes: 1

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