Question

考虑以下数据：

+-----+--------+----------+-------+
| Ref | Colour |  Month   | Value |
+-----+--------+----------+-------+
| 112 | Red    | January  |    16 |
| 113 | Black  | January  |    10 |
| 113 | Black  | January  |    11 |
| 112 | Yellow | February |    10 |
| 114 | Red    | February |     7 |
| 113 | Black  | February |    10 |
| 113 | Black  | February |    14 |
| 112 | Yellow | February |    15 |
| 113 | Black  | March    |     8 |
| 112 | Orange | March    |     1 |
| 114 | Blue   | April    |     6 |
| 113 | Black  | April    |     4 |
+-----+--------+----------+-------+

我想查询此表格以生成显示以下内容的报告：

最近连续三个月中color =“black”的refs列表 - 基于样本数据，这将返回113.

编辑，我不得不简化原来的问题。

Answer 1

您有两个部分 - 过去三个月的数据转换和过滤。可能最简单的方法是聚合然后使用having：

select ref,
       sum(case when month = 'January' then value else 0 end) as Jan,
       sum(case when month = 'February' then value else 0 end) as Feb,
       sum(case when month = 'March' then value else 0 end) as Mar,
       sum(case when month = 'April' then value else 0 end) as Apr
from t
where colour = 'Black'
group by ref
having sum(case when month = 'February' then value else 0 end) > 0 and
       sum(case when month = 'March' then value else 0 end) > 0 and
       sum(case when month = 'April' then value else 0 end) > 0;

SQL报告基于月度数据中的特定条件

1 个答案: