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Carbs

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    Ch10 edit_user script with HTML select menu

    in PHP and MySQL for Dynamic Web Sites: Visual QuickPro Guide (5th Edition)

    Posted

    Hi all,

    After working through the edit_user script in chapter ten, I thought I would like to try my hand at retrieving user information through a select dropdown. As I will have ~5000 clients, working through the list manually would be something of a chore. I came up with the following; 

    $query = "SELECT on_programme, last_name, first_name, middle_name, id FROM constant_client WHERE on_programme=1 ";
$result = mysqli_query($conn, $query);

echo  '<form action="selected_client.php" method="get">
    <fieldset>';

echo '<p><label for="current_clients">Select Client by name: </label>
        <select id="current_clients" name="current_clients">
        <option> -- Select Client -- </option>';

        while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {
          echo '<option>'.$row['id'].' '.ucwords($row['last_name']).', '.ucwords($row['first_name']).' '.ucwords($row['middle_name']).'</option>';  
        }

echo '</select>';
      
      echo '<input type="submit" name="submit" value="Go!">
<input type="hidden" name="id" value="'.$row['id'].'">';

    The above populates the dropdown menu, but I am receiving an "array offset type null" error on submission of the form, because the $row['id'] variable doesn't appear to be set outside the while loop.

    Any suggestions would be greatly appreciated.

    edit_user.php script, chapter 10

    in PHP and MySQL for Dynamic Web Sites: Visual QuickPro Guide (5th Edition)

    Posted

    On 5/7/2020 at 10:24 AM, Larry said:

    Ah, okay. So you're only having this problem when you click submit to update the information? If so, I think that's because of the extra spaces around the stored value here: 

    
 value=" '. $id .' "

    If you look at the HTML source of the page you should see the value stored as " 1 ". I wouldn't think that would cause this problem but I suspect it is. 

    Larry, you're completely correct. I thought the whitespace would be ignored, so just added those to make it more readable for me, but there you go. Thank you very much for following up!

    edit_user.php script, chapter 10

    in PHP and MySQL for Dynamic Web Sites: Visual QuickPro Guide (5th Edition)

    Posted

    Hi Larry,

      First up, great book, I'm really enjoying working through it.

    I'm having an issue with editing a user as per chapter 10, code below; 

    <?php

echo '<h1>Edit a User</h1>';


if ((isset($_GET['id'])) && (is_numeric($_GET['id']))) {
  $id = $_GET['id'];
} elseif ((isset($_POST['id'])) && (is_numeric($_POST['id']))) {
  $id = $_POST['id'];
} else { # no valid id, kill the script
  echo '<p>Yo this page has been accessed in error</p>';
  exit();
}

require("connect.php");

if ($_SERVER['REQUEST_METHOD'] == 'POST') {

  $errors = [];

    # check for first name
    if (empty($_POST['first'])) {
      $errors[] = 'You forgot to enter your first name';
    } else {
      $fn = mysqli_real_escape_string($conn, trim($_POST['first']));
    }

    #check for last name
    if (empty($_POST['last'])) {
      $errors[] = 'You forgot to enter your last name';
    } else {
      $ln = mysqli_real_escape_string($conn, trim($_POST['last']));
    }

    # check for email address
    if (empty($_POST['email'])) {
      $errors[] = 'You forgot to enter your email address';
    } else {
      $e = mysqli_real_escape_string($conn, trim($_POST['email']));
    }

    # check for errors, then if everything is ok proceed
    if (empty($errors)) {

      #test for unique email address
      $query = "SELECT id FROM users WHERE email='$e' AND id != $id";
      $result = @mysqli_query($conn, $query);

      if (mysqli_num_rows($result) == 0) {
        # make the query
        $query = "UPDATE users SET first='$fn', last='$ln', email='$e'
        WHERE id=$id LIMIT 1";
        $result = @mysqli_query($conn, $query);

        if (mysqli_affected_rows($conn) == 1) { // if it ran fine

          # print a message
          echo '<p>The User has been edited.</p>';
        } else {
          #print an error message
          echo '<p>The User could not be edited, sorry.</p>';
          echo '<p>' . mysqli_error($conn) . '<br>Query: ' . $query . '</p>';
        }

      } else {
        # the email address has already been registered
        echo '<p>The email address has already been registered.</p>';
      }


    } else {
      #report the errors
      echo '<p>The following error(s) occurred: <br>';
      foreach ($errors as $msg) {
        echo " - $msg<br>\n";
      }
      echo '</p><p>Please try again</p>';

    } # end of IF conditional

} # end of submit conditionals

# show the form

#retrieve user information
$query = "SELECT first, last, email FROM users WHERE id=$id";
$result = mysqli_query($conn, $query);

if (mysqli_num_rows($result) == 1) {

  #user ID is valid, show form

  # get user information
  $row = mysqli_fetch_array($result, MYSQLI_NUM);

  #create the form
  echo '<form action="edit_user.php" method="post">
    <p>First Name: <input type="text" name="first" size="15" maxlength="15"
      value=" '. $row[0] .' "></p>
    <p>Last Name: <input type="text" name="last" size="15" maxlength="30"
      value=" '. $row[1] .' "></p>
    <p>Email Address: <input type="email" name="email" size="20" maxlength="60"
      value=" '. $row[2] .' "></p>
    <p><input type="submit" name="submit" value="Submit"></p>
    <input type="hidden" name="id" value=" '. $id .' ">
    </form>';

} else {

  # not a valid user
  echo '<p>Hey this page has been accessed in error!</p>';

}

mysqli_close($conn);


 ?>

    I'm getting the error from the GET/POST conditional in the beginning where the $id variable is set (as in the exit() function runs and $id is not set). I can see from running through the links from view_users.php to the edit_users.php page that the GET request is showing the user id in the address bar, and if I echo $id after the first conditional I get the id for the user. Additionally when I access edit_users.php the sticky forms are prefilled with the user data, so something somewhere is working. I just wanted to check that I hadn't made a syntax error or mislabeled something somewhere that I can't see that might lead to this error.

     

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