Question

我的sql查询有问题。我想在查看之前获得没有（0）订单的订单的客户ID列表，并且在查看之前获得一（1）个订单的订单。以下查询为我提供了第三行（count_compl_ord_before_d_1）的预期结果，但第二行没有结果（count_compl_ord_before_d_0）：

SELECT created_at AS d, customer_id AS b,
(SELECT customer_id FROM orders WHERE customer_id = b AND created_at < d AND status = 'complete' HAVING COUNT(created_at) = 0 ) AS count_compl_ord_before_d_0,
(SELECT customer_id FROM orders WHERE customer_id = b AND created_at < d AND status = 'complete' HAVING COUNT(created_at) = 1 ) AS count_compl_ord_before_d_1
FROM orders
WHERE status = 'complete'
AND created_at >= '2017-06-08'

但是，当我运行以下内容时，我会得到所有不同的金额，从0到xxx为count_compl_ord_before_d：

SELECT created_at AS d, customer_id AS b,
  (SELECT COUNT(created_at) FROM orders
   WHERE customer_id = b AND created_at < d
     AND status = 'complete') AS count_compl_ord_before_d
FROM orders
WHERE status = 'complete'
AND created_at >= '2017-06-08'

HAVING COUNT(created_at) = 0是否有问题？

我不太了解SQL，但我想了解更多，所以我很感激解释。

提前致谢！干杯

SQL如何获得0作为输出（HAVING COUNT（））

0 个答案: