迷失在Google SQL海洋：3道题目让你望而却步？

2023-09-18 18:06:43







## **面纱揭开：Google SQL面试题** 

一踏入Google的面试室，你会发现面前摆放着一张白纸，上面密密麻麻地写满了SQL查询语句。别慌张，深呼吸，冷静分析。毕竟，大厂的殿堂可不是随随便便就能登上的。

**1. 统计出客户在过去一年里购买过的不同商品数量** 

```sql
SELECT customer_id, COUNT(DISTINCT product_id) AS distinct_products_purchased
FROM orders
WHERE order_date BETWEEN DATE('now', '-1 year') AND DATE('now')
GROUP BY customer_id;

2. 找出每种商品在过去一个月内最受欢迎的购买时间段

SELECT product_id, 
       strftime('%H:00-%H:59', order_date) AS hour_of_day,
       COUNT(*) AS orders_in_hour
FROM orders
WHERE order_date BETWEEN DATE('now', '-1 month') AND DATE('now')
GROUP BY product_id, hour_of_day
ORDER BY product_id, orders_in_hour DESC;

3. 识别出过去一年里购买次数最多的前10位客户

SELECT customer_id, 
       COUNT(*) AS total_orders
FROM orders
WHERE order_date BETWEEN DATE('now', '-1 year') AND DATE('now')
GROUP BY customer_id
ORDER BY total_orders DESC
LIMIT 10;