CS521 Final Term Current Subjective by MS Team

CS521 - Short Questions & Answers

1. Update SQL Query

UPDATE Categories SET CategoryName = ' Web' WHERE CategoryName = ' Business';

1. Reference: Week 11, Topic 91

2. PHP Methods for:

o Removing session variable:

session_unset(); // removes all session variables

o Destroying session:

session_destroy(); // ends the session

2. Reference: Week 13, Topic 114

3. Using $_FILES in PHP

PHP uses the $_FILES array to handle file uploads. Key steps:

o HTML form should use: enctype="multipart/form-data" o Use $_FILES['fileInputName']['name'], ['type'], ['tmp_name'], ['error'], ['size'] for file details o Example:

if ($_FILES['myFile']['error'] == UPLOAD_ERR_OK) {

move_uploaded_file($_FILES['myFile']['tmp_name' ], 'uploads/' . $_FILES['myFile']['name']);

4. Benefits of AJAX

o Asynchronous communication with server o Reduces page reloads o Improves user experience o Allows partial page updates

5. What are sockets and how they differ from traditional HTML communication

o Socket: Enables full-duplex communication between browser and server.

o Difference:

 Traditional HTTP: request-response model  Web Sockets: real-time, bi-directional communication

6. Different Types of Form Validation

o Client-side (JavaScript):

 Input format, required fields, data type checks

o Server-side (PHP):

 Required info, correct data type, range check, regex

o Using PHP filters

filter_var($email, FILTER_VALIDATE_EMAIL);

7. Reference: Week 12, Topics 107–108

1. Benefits of using Transactions (with Example)

o Benefits:  Ensures data integrity  Allows rollback if an error occurs  Multiple queries act as one atomic operation o Example:

$pdo->beginTransaction(); $pdo->query("INSERT INTO Categories (CategoryName) VALUES (' Philosophy')"); $pdo->query("INSERT INTO Categories (CategoryName) VALUES (' Art')"); $pdo->commit();

If error occurs, use $pdo->rollback();

2. Syntax to Define Array in PHP + Types of Arrays

o Indexed Array:

$colors = array(" Red", " Green", " Blue");

o Associative Array:

$ages = array(" Peter"=>35, " John"=>40);

o Multidimensional Array:

$students = array( array(" Ali", 20), array(" Sara", 22)

3. Reference: Week 9, Topic 78