Retrieve All Parent Records with Optional Child Data

SELECT
  c.id AS customer_id,
  c.name AS customer_name,
  o.id AS order_id,
  o.order_date,
  o.total_amount
FROM customers c
LEFT JOIN orders o ON c.id = o.customer_id
WHERE c.id = 101;

How it works: This query utilizes a `LEFT JOIN` to retrieve all customers, including their details, along with any orders they might have placed. If a customer has no corresponding orders, the order-related columns (`order_id`, `order_date`, `total_amount`) will display as `NULL`. This is essential for scenarios where you need to see all records from one table, even if related data in another table is absent.