归一化总和 (SQL) 的汇总列 - 第 1 部分

Question

I have a table like so:

object_id | vote
1 | 2
1 | -1
1 | 5
2 | 3
2 | 1
3 | 4
3 | -2

I want this result (for this particular example, object_ids 1 and 2 are part of a group, defined elsewhere, and I'm looking for the normalized_score so that the sum always = 1. object_id 3 is part of an unused group.):

object_id | normalized_score
1 | 6/10
2 | 4/10

[added 3:05PM] 10 here is the sum of the votes for object_id in (1,2). There's a whole other set of logic to come up with the (1,2), I was just trying to give the cleanest question so people don't have to worry about that part.

[added 3:10PM] As pointed out in the comments, if the score for one of the objects is below 0, a problem arises. Here is the rule, "IF the score for any outcome_id is -x, AND that is the minimum score for the set, ADD x to all scores in order to zero-out the minimum score". I can do this on my own time though outside of SQL - so it's a bonus only if somebody has the cahones to try to tackle it in SQL.

If I do a self join, I can get the sum. I can't figure out how to get the normalized sum. Ideally this will work in both MySQL 5.x and Sqlite3. Otherwise, I can do this with two separate queries and just do the work in post-processing.

Answer 1

The comments are quite correct.. but I'll make the assumption that 10 is just some number you picked out of your... nose.

SELECT object_id AS ObjectID, SUM(vote) + '/10' AS NormalizedVote FROM table GROUP BY object_id

Enjoy.

Answer 2

-- SQL solution
SELECT 
  object_id AS ObjectID, 
  (SUM(CASE SIGN(vote) WHEN 1 THEN vote ELSE 0 END) - 
    ((CASE SIGN(MIN(vote)) WHEN -1 THEN MIN(vote) ELSE 0) * 
     (COUNT(1)))) + '/10' AS NormalizedVote
FROM table 
GROUP BY object_id

Answer 3

The solution without compensating for negative votes (I include this one because its much easier to read/understand):

SELECT object_id
,      SUM(vote) + '/' + total AS normalized_score
FROM   tabel
,      (
       SELECT sum(vote) AS total
       FROM   tabel
       ) 
GROUP BY object_id, total

Full solution:

SELECT object_id
,      SUM(vote + minvote) + '/' + (total + minvote * count) AS normalized_score
FROM   tabel
,      (
       SELECT sum(vote) AS total
       ,      CASE WHEN MIN(vote) < 0 THEN
                  -MIN(vote)
              END AS minvote
       ,      COUNT(*) AS count
       FROM   tabel
       ) 
GROUP BY object_id, total, minvote, count

(I don't have access to MySQL, so I wrote a query in Oracle and replaced || for +. Hope it works in MySQL or at least helps:))