是否有比我更快的解決方案?打印每個訂單的訂單數量products_id
我有一個表列orders_id和products_id(不能更改)
現在我想知道有獨特products_id取得多少訂單。
我嘗試了以下。但是在裝載太多行時崩潰(160'000)。
SELECT DISTINCT `products_id` , `products_name` , COUNT(*) as totalorders FROM `orders_products` ORDER BY `products_id` ASC
我也嘗試過子查詢,但是與上面相同的問題。
SELECT (SELECT count(*) FROM orders_products WHERE products_id = op.products_id) AS totalorders, products_id, products_name FROM orders_products op ORDER BY products_id ASC
你爲什麼不使用「GROUP BY」?如果這是MySQL,請發佈'EXPLAIN'輸出。 – Kermit