Question

我有这些列的CallHistory表：

CustomerId, TimeOfCall, CallResult

在CallResult中我可能有以下值： '已下订单'，'要求退货'，'技术问题'，'询问定价'等。

我想SELECT CustomerId FROM CallHistory WHERE客户至少有一次'询问定价'，但从未'放置订单'。

谢谢！

Answer 1

SELECT DISTINCT c.CustomerId
    FROM CallHistory c
    WHERE c.CallResult = 'inquired about Pricing'
        AND NOT EXISTS(SELECT 1
                           FROM CallHistory c2
                           WHERE c2.CustomerId = c.CustomerId
                               AND c2.CallResult = 'Placed Order')

Answer 2

我认为你应该可以使用没有连接或子查询的单个选择来实现它

试试这个：

SELECT CustomerId
FROM CallHistory
GROUP BY CustomerId
HAVING COUNT(CASE WHEN CallResult='Inquired about Pricing' THEN 1 ELSE NULL END) > 0
   AND COUNT(CASE WHEN CallResult='Placed Order' THEN 1 ELSE NULL END) = 0

Answer 3

SELECT CustomerId
  FROM CallHistory
 WHERE CallResult = 'Inquired about Pricing'
EXCEPT
SELECT CustomerId
  FROM CallHistory
 WHERE CallResult = 'Placed Order';

SELECT语句检索从未发生过的事情

3 个答案: