sql - group by子句未产生预期的总和

Question

我正在开发iPhone应用程序并使用sqlite数据库。

我有如下的answers_ELA表：

Id    | observation_id    | question_no    | answer    | answer2
-------------------------------------------------------------------
1     | 60                | 0              | 2         | 1
2     | 60                | 1              | 3         | 4
3     | 61                | 0              | 3         | 4
4     | 61                | 1              | 3         | 2
5     | 62                | 0              | 3         | 1
6     | 62                | 1              | 1         | 2

我想要结果

question_no    | total
-------------------------
0              | 14
1              | 15

但它给

question_no    | total
-------------------------
0              | 4
1              | 3

仅用于最后一个observation_id的平均值，即62

查询如下：

SELECT 
    question_no,
    (answer+answer2) total
FROM 
    answers_ELA 
WHERE
    observation_id IN(60,61,62) 
GROUP BY 
    question_no

这有什么问题，我应该怎么做才能获得理想的结果。

Answer 1

试试这个：

SELECT question_no, SUM(answer+answer2) total
FROM answers_ELA 
WHERE observation_id IN (60,61,62) 
GROUP BY question_no