<?php
// Database credentials
$servername = "localhost";
$username = "your_username";
$password = "your_password";
$dbname = "your_database";

try {
    // 1. Create database connection (DSN includes the charset)
    $dsn = "mysql:host=$servername;dbname=$dbname;charset=utf8mb4";
    $conn = new PDO($dsn, $username, $password);
    
    // 2. Set the PDO error mode to exception
    $conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
    echo "Connected successfully.<br><br>";

    // ==========================================
    // EXAMPLE 1: Inserting data into the database (INSERT)
    // ==========================================
    // Assuming you have a 'users' table with 'first_name', 'last_name', and 'email' columns
    $sql_insert = "INSERT INTO users (first_name, last_name, email) 
                   VALUES ('John', 'Doe', 'john.doe@example.com')";
    
    // exec() is used for queries that don't return a result set
    $conn->exec($sql_insert);
    
    // Get the ID of the last inserted row
    $last_id = $conn->lastInsertId();
    echo "✅ New record created successfully. The ID of the new user is: " . $last_id . "<br><br>";

    echo "<hr>";

    // ==========================================
    // EXAMPLE 2: Reading data from the database (SELECT)
    // ==========================================
    $sql_select = "SELECT id, first_name, last_name FROM users";
    
    // query() is used for running standard SELECT statements
    $stmt = $conn->query($sql_select);
    
    // Check if the query returned any rows
    if ($stmt->rowCount() > 0) {
        echo "<strong>User List:</strong><br>";
        
        // Loop through the results row by row using FETCH_ASSOC
        while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
            echo "ID: " . $row["id"] . " | Name: " . $row["first_name"] . " " . $row["last_name"] . "<br>";
        }
    } else {
        echo "No records found in the database.";
    }

} catch (PDOException $e) {
    // Catch any database errors and display them safely
    echo "❌ Database Error: " . $e->getMessage();
}

// 3. Close the connection
// In PDO, closing the connection is done by setting the variable to null
$conn = null;
?>