SELECT 查询中的公用表表达式

Created: November-22, 2018

公用表表达式支持提取较大查询的部分。例如：

WITH sales AS (
  SELECT 
    orders.ordered_at,
    orders.user_id,
    SUM(orders.amount) AS total
  FROM orders
  GROUP BY orders.ordered_at, orders.user_id
)
SELECT 
  sales.ordered_at,
  sales.total,
  users.name
FROM sales 
JOIN users USING (user_id)