Question

我有一个表格，其中包含有关联系人呼叫尝试的信息。相关领域如下：

Contact     Date        Result
John Smith  1/8/2013    VM
John Smith  1/9/2013    VM
John Smith  1/10/2013   Busy Signal
John Smith  1/11/2013   Hang Up                   <--- Connect
Jane Smith  1/8/2013    VM
Jane Smith  1/9/2013    Scheduled Call Back       <--- Connect
Jane Smith  1/10/2013   VM
John Doe    1/8/2013    Not Interested            <--- Connect
Jane Doe    1/8/2013    Busy Signal
Jane Doe    1/9/2013    Busy Signal
Jane Doe    1/10/2013   Busy Signal

我正在尝试计算尝试次数，直到通过联系人连接（而不是第一次连接后的任何尝试），或者到目前为止没有连接的尝试次数，我正在麻烦。在这种情况下表示连接的结果将是挂机，预定回拨和不感兴趣。

我想要的是：

Contact       Attempts
John Smith    4
Jane Smith    2
John Doe      1
Jane Doe      3

有办法做到这一点吗？任何帮助将不胜感激。

Answer 1

您需要考虑使用GROUP BY：

SELECT Contact, COUNT(*) Attempts
FROM Contacts 
WHERE Result NOT IN ('Hang Up','Scheduled Call Back','Not Interested')
GROUP BY Contact

- 编辑

没有意识到OP的要求。在他接受另一个答案之前无法完成这个......

祝你好运。

Answer 2

对于MySQL：

SELECT 
    t.Contact, COUNT(*) AS Attempts
FROM 
    tableX AS t
  JOIN 
          ( SELECT DISTINCT contact
            FROM tableX
          ) AS d
      LEFT JOIN
          ( SELECT contact, 
                   MIN(date) AS date 
            FROM tableX
            WHERE result IN ('Hang Up', 'Scheduled Call Back', 'Not Interested')
            GROUP BY contact
          ) AS g
        ON d.contact = g.contact
    ON  t.contact = d.contact
    AND t.date <= COALESCE(g.date, '9999-12-31')
GROUP BY
    t.contact ;

SQL - 直到特定结果的列的计数

2 个答案: