JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B.Tech III WEB TECHNOLOGIES Previous Question Paper (August - 2022 - R18)

MySQL is an open-source relational database management system. Its advantages include high performance, ease of use, strong data security, and wide support for various storage engines. Its disadvantages involve limitations in handling extremely large datasets compared to enterprise-grade databases like Oracle, and potential performance issues with complex nested queries.

PHP is a server-side scripting language designed for web development. Its advantages include ease of integration with databases, a vast ecosystem of frameworks and libraries, and broad hosting support. Its disadvantages include inconsistent language design, potential security vulnerabilities if not coded carefully, and lower performance for CPU-intensive tasks compared to compiled languages.

To connect to MySQL from PHP, the following steps are required: 1) Define database credentials (host, username, password, database name). 2) Initialize a connection using the mysqli_connect() function or the PDO class. 3) Verify the connection status. 4) Execute a SQL query using mysqli_query(). 5) Fetch results using functions like mysqli_fetch_assoc(). 6) Close the connection using mysqli_close().

Example script:

<?php
$conn = mysqli_connect('localhost', 'root', '', 'test_db');
if (!$conn) { die('Connection failed: ' . mysqli_connect_error()); }
$sql = 'SELECT id, name FROM users';
$result = mysqli_query($conn, $sql);
if (mysqli_num_rows($result) > 0) {
    while($row = mysqli_fetch_assoc($result)) {
        echo 'ID: ' . $row['id'] . ' - Name: ' . $row['name'] . '<br>';
    }
} else { echo '0 results'; }
mysqli_close($conn);
?>