SQLite SELECT除了单列有重复的地方

Question

如何确保s.user_id和w.stage_id没有重复的行？您可以在screengrab中看到user_id 117出现在两行中。我想阻止这种情况 - 可能只包括查询中的最新提交？

我的返回数据如下：

我的查询：

SELECT DISTINCT r.breakout_id, r.case_id, r.stage_id, r.chart_id, s.stage1_choice,s.user_id,w.stage1,w.user_id
FROM Results as r, Submissions as s, Switch as w
WHERE r.breakout_id = '1' AND s.breakout_id = '1' AND w.breakout_id = '1' AND s.user_id = w.user_id AND w.case_id = r.case_id AND s.case_id = r.case_id AND s.stage1_choice IS NOT NULL ORDER BY w.user_id

Answer 1

试试这个：

SELECT r.breakout_id, r.case_id, r.stage_id, r.chart_id, 
s.stage1_choice,s.user_id,max(w.stage1),w.user_id
FROM Results as r, Submissions as s, Switch as w
WHERE r.breakout_id = '1' AND s.breakout_id = '1' AND w.breakout_id = '1' AND s.user_id = w.user_id 
AND w.case_id = r.case_id AND s.case_id = r.case_id AND 
s.stage1_choice IS NOT NULL 
GROUP BY r.breakout_id, r.case_id, r.stage_id, r.chart_id, 
s.stage1_choice,s.user_id,w.user_id
ORDER BY w.user_id;