SQL计算每月记录的项目，但仍未批准

Question

我有一个日历表就是这个。

c_calendardate
1/1/2015
2/3/2015
.
.
.
10/18/2015
10/19/2015

和物料请求上的交易记录。

+------------+------------+-------------+-----------+----------+
| Requestor  |   Item     | Date_Entry  | Approver  |  Status  |
+------------+------------+-------------+-----------+----------+
| Bob        | PCB        | 1/2/2015    | Admin     | Open     |
| Bob        | PCB        | 3/19/2015   | Admin     | Approved |
| May        | UTP Cable  | 1/1/2015    | Admin     | Open     |
| May        | UTP Cable  | 4/20/2015   | Admin     | Approved |
| Joseph     | RJ45       | 2/10/2015   | Admin     | Open     |
| Joseph     | RJ46       | 6/3/2015    | Admin     | Approved |
+------------+------------+-------------+-----------+----------+

我想要的输出是什么。

+------------+-----------------------+
|   Month    | Total_Open_Each_Month |
+------------+-----------------------+
| 2015-Jan   |                     2 |
| 2015-Feb   |                     3 |
| 2015-Mar   |                     3 |
| 2015-Apr   |                     2 |
| 2015-May   |                     1 |
| 2015-Jun   |                     1 |
| 2015-Jul   |                     0 |
| 2015-Aug   |                     0 |
| 2015-Sept  |                     0 |
| 2015-Oct   |                     0 |
| 2015-Nov   |                     0 |
| 2015-Dec   |                     0 |
+------------+-----------------------+

上面的输出是每个月计算每个未清项目，如果记录仍然没有被批准，每个月仍会计算，有人可以帮我查询吗？

Answer 1

您可以使用[OptionalFiled]和DATE_FORMAT()

GROUP BY

Answer 2

你可以这样试试

SELECT count(id),
STR_TO_DATE(Date_Entry, '%m/%d/%Y') as date1
MONTHNAME(STR_TO_DATE(Date_Entry, '%m/%d/%Y') ),
YEAR(STR_TO_DATE(Date_Entry, '%m/%d/%Y') )
FROM
Table_name
WHERE
Status =  'open'
group by date1