Question

我有一个问题是我无法从每一天的表格结果中获取每行的ID。我在phpMyAdmin中的表是这样的：

  ------------------------------------
  |   Date_id  |        Date         |
  ------------------------------------
  |    1       |  2014-05-13         |
  |    2       |  2014-06-04         |
  |    3       |  2014-07-09         |
  |    4       |  2014-08-13         |
  |    5       |  2014-09-12         |
  |    6       |  2014-10-15         |
  |    7       |  2014-11-19         |
  |    8       |  2014-12-10         |
  |    9       |  2015-01-14         |
  |    10      |  2015-02-11         |
  |    11      |  2015-03-10         |
  |    12      |  2015-04-15         |
  |    13      |  2015-05-12         |
  |    14      |  2015-06-12         |
  ------------------------------------

当我编写代码php以使Date_id进行编辑但仍显示第1行时，每列只有一个id相同而第二行，第三行......也只显示一个id。我的表格是这样的：

------------------------------------------------------------------------------------------
|   Year  | Jan | Feb | Mar | April | May | June | July | Aug | Sept | Oct | Nov | Dec |
------------------------------------------------------------------------------------------
| 2014    |     |     |     |       | 13  | 04   | 07   | 13  | 12   | 15  | 19  | 10  |
----------------------------------------------------------------------------------------
| 2015    | 14  | 11  | 10  |  15   | 12  | 12   |      |     |      |     |     |     |
----------------------------------------------------------------------------------------

这是我使用它的查询代码：

select year(`Date`) as `year`,Date_id,
   max(case when month(date) = 1 then day(`date`) end) as Jan,
   max(case when month(date) = 2 then day(`date`) end) as Feb,
   max(case when month(date) = 3 then day(`date`) end) as Mar,
   max(case when month(date) = 4 then day(`date`) end) as Apr,
   max(case when month(date) = 5 then day(`date`) end) as May,
   max(case when month(date) = 6 then day(`date`) end) as Jun,
   max(case when month(date) = 7 then day(`date`) end) as Jul,
   max(case when month(date) = 8 then day(`date`) end) as Aug,
   max(case when month(date) = 9 then day(`date`) end) as Sep,
   max(case when month(date) = 10 then day(`date`) end) as Oct,
   max(case when month(date) = 11 then day(`date`) end) as Nov,
   max(case when month(date) = 12 then day(`date`) end) as Dec
from table t
group by year(date)
order by year(date)

我的预期结果是它将显示为我的表格，它将从每天获得ID 我该如何编写查询？谢谢你。

Answer 1

您的查询看起来不错但有一个小问题。您正在使用保留关键字dec来破坏查询。你需要反推它，这是修改后的查询

select year(`Date`) as `year`,Date_id,
   max(case when month(date) = 1 then day(`date`) end) as Jan,
   max(case when month(date) = 2 then day(`date`) end) as Feb,
   max(case when month(date) = 3 then day(`date`) end) as Mar,
   max(case when month(date) = 4 then day(`date`) end) as Apr,
   max(case when month(date) = 5 then day(`date`) end) as May,
   max(case when month(date) = 6 then day(`date`) end) as Jun,
   max(case when month(date) = 7 then day(`date`) end) as Jul,
   max(case when month(date) = 8 then day(`date`) end) as Aug,
   max(case when month(date) = 9 then day(`date`) end) as Sep,
   max(case when month(date) = 10 then day(`date`) end) as Oct,
   max(case when month(date) = 11 then day(`date`) end) as Nov,
   max(case when month(date) = 12 then day(`date`) end) as `Dec`
from test t
group by `year`
order by `year`

如果您不想要，可以从选择列表中取出Date_id。

<强> DEMO

MySQL Select Query无法连续获取每天的ID

1 个答案: