php - 如何获得客户提交帖子的天数？

Question

如何获得客户提交的帖子的天数？
图片告诉我想得到什么。我不知道如何将mysql中的日期总结为天，有人帮忙吗？
需要php来做这些工作吗？

select ? from table where ?

Answer 1

SELECT customers_id, SUM(customers_id) as sum_days FROM table GROUP BY customers_id,   DAY(date);

那应该这样做。

Answer 2

这是我的猜测：

SELECT `customers_id`, COUNT(DISTINCT(`date`)) as sum_days
FROM `table` GROUP BY `customers_id`

我在一张我正在修补的小桌子上试了一下，得到了以下结果：

SELECT author, entry_date FROM table;
+--------+------------+
| author | entry_date |
+--------+------------+
|      5 | 0000-00-00 |
|      8 | 0000-00-00 |
|      8 | 0000-00-00 |
|      8 | 2013-02-28 |
|      8 | 2013-02-28 |
|      8 | 2013-03-02 |
+--------+------------+

多田

SELECT author, COUNT(DISTINCT(entry_date)) as num_days 
FROM table GROUP BY author ;
+--------+----------+
| author | num_days |
+--------+----------+
|      5 |        1 |
|      8 |        3 |
+--------+----------+
2 rows in set (0.00 sec)

另外，这是我之前在同一张桌子上回复的结果：

SELECT author, SUM(author) as sum_days FROM table 
GROUP BY author, DAY(entry_date);
+--------+----------+
| author | sum_days |
+--------+----------+
|      5 |        5 |
|      8 |       16 |
|      8 |        8 |
|      8 |       16 |
+--------+----------+
4 rows in set (0.00 sec)