T-SQL查询产生不同的输出

Question

我有两个代码片段，它们产生不同的输出。请问任何人都可以建议我犯错的地方吗？

第一段代码：

sum[i] = 2;
i = i + 1;

第二段代码：

select 
    a.contest_id,
    B.hacker_id,
    B.name,
    SUM(e.total_submissions)total_submissions,
    SUM(e.total_accepted_submission) total_accepted_submission,
    SUM(total_view)total_view,
    SUM(total_unique_views) total_unique_views 
from  
    Contests b 
inner join 
    Colleges a on A.contest_id = B.contest_id
left join  
    Challenges c on a.college_id = c.college_id 
left join 
    (select 
         challenge_id,
         SUM(total_views) total_view,
         sum(total_unique_views) total_unique_views 
     from 
         View_Stats 
     group by challenge_id) d on c.challenge_id = d.challenge_id 
left join 
    (select 
         challenge_id,
         SUM(total_submissions) total_submissions,
         SUM(total_accepted_submission) total_accepted_submission 
     from  
         Submission_Stats 
     group by 
         challenge_id) e on e.challenge_id = d.challenge_id
group by 
    a.contest_id, b.hacker_id, B.name 
having 
    (sum(total_submissions) +
    sum(total_accepted_submission) +
    sum(total_view) + sum(total_unique_views)) <> 0
order by
    a.contest_ID

问题在于总提交的值和total_accepted_submission

Answer 1

第一个示例中有LEFT JOIN Challenges，第二个示例中有INNER JOIN Challenges。