test_connection.php

<?php

// 1. Include our database file (which sets up $pdo)
require_once __DIR__ . '/database.php';

// 2. Set the response header to JSON format
header('Content-Type: application/json');

try {
    // 3. Execute a simple raw SQL query to test the active connection socket
    $stmt = $pdo->query("SELECT VERSION()");
    $version = $stmt->fetchColumn();

    // 4. Output a successful connection message along with the DB engine details
    echo json_encode([
        "status" => "success",
        "message" => "PHP successfully connected to the PostgreSQL Docker container!",
        "database_version" => $version
    ]);

} catch (\PDOException $e) {
    // 5. Handle any runtime execution errors gracefully
    http_response_code(500);
    echo json_encode([
        "status" => "error",
        "message" => "Query execution failed: " . $e->getMessage()
    ]);
}