如果使用php满足某些条件，则更新数据库中的值

im on the quest of figuring out the php/sql/html code I was left. I am just trying to change a number value in the database if a certain condition is met. ill give a breakdown in order to not get this flagged as a duplicate.

• tutorials that i see in regarding to php and sql update tends to show that you have to write down a variable to connect to the database and update from there:

W3SCHOOLS EXAMPLE:

<?php
$servername = "localhost";
$username = "username";
$password = "password";
$dbname = "myDB";

// Create connection
$conn = new mysqli($servername, $username, $password, $dbname);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
} 

$sql = "UPDATE MyGuests SET lastname='Doe' WHERE id=2";

if ($conn->query($sql) === TRUE) {
    echo "Record updated successfully";
} else {
    echo "Error updating record: " . $conn->error;
}

$conn->close();
?>

• the code i was given however, does it differently. it uses a "public function" in order to connect to the database. here is a example of a working part of the code where a user's information is changed from what is typed in textfields via "UpdateObj"

CHANGING SETTINGS: (named "settings-profile.vc.php")

<?php

    $routePath = "../";

      require_once($routePath . "_config/db.php");
        $dbConfig = new config_db();
        $db = $dbConfig->init();

      require_once($routePath . "_config/app.php");

      require_once($routePath . "_lib/c/Photo_Resizer.php");

      require_once($routePath . "_mc/UsrCustomerMembershipOrder.mc.php");
      $mcUsrCustomerMembershipOrder = new UsrCustomerMembershipOrder_MC();

      require_once($routePath . "_mc/UsrCustomer.mc.php");
      $mcUsrCustomer = new UsrCustomer_MC();

      require_once($routePath . "_mc/UsrCustomerProfile.mc.php");
      $mcUsrCustomerProfile = new UsrCustomerProfile_MC();

      require_once($routePath . "_mc/Product.mc.php");
      $mcProduct = new Product_MC();

      require_once($routePath . "_mc/ProductTag.mc.php");
      $mcProductTag = new ProductTag_MC();

      require_once($routePath . "_mc/Merchant.mc.php");
      $mcMerchant = new Merchant_MC();

      require_once($routePath . "_mc/ProductTagLink.mc.php");
      $mcProductTagLink = new ProductTagLink_MC();

      /********** Implementation **********/

      // Check Session Credentials and auto-login
      if ($_SESSION['usrcustomerid'] == '') {
        header('Location: signout.php'); die();
      }

      $usrcustomerid = $_SESSION['usrcustomerid'];
      $rowUsrCustomerProfile = $mcUsrCustomerProfile->SelectObj_ByUsrCustomerId($db, $usrcustomerid);

      // On Register Click
      if (isset($_POST['save']) && $_POST['save'] == 'SAVE')
      {
        $err_msg = '';
        $fname = $_POST['fname'];
        $lname = $_POST['lname'];
        $birthdate = $_POST['birthdate'];
        $birthdate = date('Y-m-d H:i:s', strtotime($birthdate));
        $country = $_POST['country'];
        $address = $_POST['address'] . ' ';
        $contact = $_POST['contact'];

        if ($birthdate == '') { $err_msg .= '<li>Enter your Birth Date. </li>'; }
        if ($lname == '') { $err_msg .= '<li>Enter your last name. </li>'; }
        if ($fname == '') { $err_msg .= '<li>Enter your first name. </li>'; }
        if ($contact == '') { $err_msg .= '<li>Enter your contact number. </li>'; }

        /**** If form is valid then Save to database ****/
        if($err_msg == '')
        {
          $mcUsrCustomerProfile->UpdateObj($db, $usrcustomerid, $fname, $lname, $birthdate, $country, $address, $contact);
        }
      } ?>

• it is using a public function from the file "UsrCustomerProfile.mc.php"

  public function UpdateObj($db, $usrcustomerid, $fname, $lname, $birthdate, $country, $address, $contact) {
      $stmt = $db->prepare(
        " UPDATE usr_customer_profile
          SET fname = :fname, lname = :lname, birthdate = :birthdate, country = :country, address = :address, contact = :contact
          WHERE usrcustomerid = :usrcustomerid"
      );
  
      $stmt->bindValue(':usrcustomerid', $usrcustomerid, PDO::PARAM_INT);
      $stmt->bindValue(':fname', $fname, PDO::PARAM_STR);
      $stmt->bindValue(':lname', $lname, PDO::PARAM_STR);
      $stmt->bindValue(':birthdate', $birthdate, PDO::PARAM_STR);
      $stmt->bindValue(':country', $country, PDO::PARAM_STR);
      $stmt->bindValue(':address', $address, PDO::PARAM_STR);
      $stmt->bindValue(':contact', $contact, PDO::PARAM_STR);
      $stmt->execute();
      $rowAffected = $stmt->rowCount();
  
      return $rowAffected;
    }
  

  • here is a screenshot of the usr_customer_profile table in the database:

  

  • now i have a php code where a user's status is determined by what package id he/she has

          <?php
              // Check Session Credentials and auto-login
              $packageid = $_SESSION['usrcustomer_packageid'];
    
                if ($packageid == 0) {
                    $ribbon = 'ribbon-guest';
                  } else if ($packageid <= 1) {
                    $ribbon = 'ribbon-elite';
                  } else if ($packageid == 2) {
                    $ribbon = 'ribbon-premium';
                  } else if ($packageid == 3) {
                    $ribbon = 'ribbon-luxury';
                  }
    
                  echo('Status: <a href="membership.php"><img src="../img/'.$ribbon.'.png" class="small-icon"></a> ');
    
                    if ($packageid == 0) {
                    echo ('Guest <br/>');
                  } else if($packageid == 1) {
                    echo('Elite Member <br/>');
                  } else if($packageid == 2) {
                    echo('Premium Member <br/>');
                  } else if($packageid == 3) {
                    echo('Luxury Member <br/>');
                  }
    
                  if ($_SESSION['usrexpirationdays'] <= 0) {
                    $_SESSION['usrcustomer_packageid'] = 0;
                  } else if (isset($_SESSION['usrexpirationdate'])) {
                  echo(' <small>(Expiry: ' . $_SESSION['usrexpirationdate'] . ', ' . $_SESSION['usrexpirationdays'] . ' days remaining)</small>');
    
                  }
                ?>
                <?php } else { ?>
    

• there is a login feature used hence the use of the "$_SESSION"
• as you can see with the screenshot of the database, if a user's expiration date has gone by, the packageid becomes 0, and displays guest.

"if ($_SESSION['usrexpirationdays'] <= 0) { $_SESSION['usrcustomer_packageid'] = 0;"

• the problem is that this only updates the display but not the database value, what else should i add to achieve this?
• i provided enough information to show that i analyzed the code before asking my concern, any help would be great thank you.