T-SQL：使用case语句进行分区

Question

我有下表：

| RoomID | OrderID | Occupancy | Status        |
+--------+---------+-----------+---------------+
| 01     | 101     | Vacant    | inspection    |
| 01     | 102     | Occupied  | Preservation  |
| 01     | 103     | Occupied  | inspection    |
| 01     | 104     | Vacant    | inspection    |
| 02     | 201     | Vacant    | inspection    |
| 02     | 202     | Occupied  | inspection    |
| 02     | 203     | Vacant    | inspection    |
| 03     | 301     | Vacant    | inspection    |
| 03     | 302     | Occupied  | inspection    |
| 03     | 303     | Occupied  | Preservation  |
| 03     | 304     | Occupied  | Preservation  |
| 04     | 401     | Occupied  | inspection    |
| 04     | 402     | Occupied  | inspection    |
| 04     | 403     | Vacant    | Preservation  |
| 04     | 404     | Occupied  | inspection    |

我需要在RoomID =＆＃39;占用的Occupancy级别上提取数据。和Status =＆＃39;保存＆＃39;在任何给定RoomID的实例中。

结果应如下所示：

| RoomID | Flag    |
+--------+---------+
| 01     | 1       |
| 02     | 0       |
| 03     | 1       |
| 04     | 0       |

我的印象是这很简单，但我现在看不到它，请提前感谢您的帮助！

Answer 1

您可以使用条件聚合。

i > 0

Answer 2

您也可以使用UNION。

使用以下查询

{{1}}