Question

我有一个包含id和answer列的表，如下所示：

| id | answer |
| 1  |  Yes   |
| 2  |   No   |
| 3  | Unsure |
| 1  |  No    |
| 1  | Unsure |
| 3  |  Yes   |
| 2  | Unsure |
| 4  | NULL   |
| 4  | Unsure |
| 4  | No     |

我希望输出的方式是，如果用户ID已经回答'是'（例如id 1），那么最终输出应该为1。但是如果用户标识回答“否”和“空”，则输出应为“否” 此外，如果用户ID已回答“不确定”，“否”或“不确定”和“空”，则输出应为“不确定”

最终输出：

| id | answer |
| 1  | Yes    |
| 2  | Unsure |
| 3  | Yes    |
| 4  | Unsure |

Answer 1

CASE WHEN (.Answer IS NULL OR .Answer = 'No') THEN 'NO' ELSE (.Answer) END AS 'FILTERED ANSWER'

这可以帮到你吗？

Answer 2

您希望对此使用聚合和case逻辑：

select id,
       (case when sum(case when Answer = 'yes' then 1 else 0 end) > 0
             then 'yes'
             when sum(case when answer = 'unsure' then 1 else 0 end) > 0
             then 'unsure'
             else 'no'  -- or perhaps max(answer)
        end) as answer
from t
group by id;

如果唯一的可能性是“是”，“不”，“不确定”和NULL，那么你可以采取捷径：

select id,
       (case when max(Answer) = 'yes'
             then 'yes'
             when max(answer) = 'unsure'
             then 'unsure'
             else 'no'  -- or perhaps max(answer)
        end) as answer
from t
group by id;

用于比较计数大于1的记录的SQL查询

2 个答案: