sql WITH关键字

Posted 2021-05-13

\!h COUNT query embedded into a WITH statement (creates a temporary table)
WITH previous_query AS (
SELECT customer_id,
COUNT(subscription_id) as subscriptions
FROM orders
GROUP BY customer_id)

\!h A column from the previous query joined with a column from a separate table
SELECT customers.customer_name, 
previous_query.subscriptions
FROM previous_query
JOIN customers
ON customers.customer_id = previous_query.customer_id;