SELECT id, title, posted, duration, thumbnail, email, first_name
FROM customers
Here is a brief example (too long for comments) since you're using MySQLi:
Object oriented style:
/* prepare query */
$stmt = $mysqli->prepare("SELECT id, title, posted, duration, thumbnail, email, first_name FROM customers");
/* execute query */
$stmt->execute();
Procedural style (where $conn is the database connection):
/* prepare */
$stmt = mysqli_prepare($conn, "SELECT id, title, posted, duration, thumbnail, email, first_name FROM customers");
/* execute query */
mysqli_stmt_execute($stmt);
