mysql - 如何先按 A 列排序，返回 top-3，然后在一个查询中按 B 列排序结果？

Question

(请参阅 SQLFiddle 以获取本文的工作示例)

我有一张股票信息表，如下:

sp100_id  _date         bullishness  agreement
----------------------------------------------
1         2011-03-16    1.01          0.33
1         2011-03-17    0.85          1.28
1         2011-03-18    0.89          1.25
1         2011-03-21    1.46          1.21
1         2011-03-22    0.39          2.53
2         2011-03-16    3.07          1.27
2         2011-03-17    2.09          0.80
2         2011-03-18    0.91          0.12
2         2011-03-21    1.50          0.00
2         2011-03-22    2.62          1.10
3         2011-03-16    0.73          1.13
3         2011-03-17    1.13          1.21
3         2011-03-18    1.12          0.45
3         2011-03-21    1.00          1.01
3         2011-03-22    1.00          0.53
4         2011-03-16    0.40          1.10
4         2011-03-17    2.40          0.03
4         2011-03-18    3.16          0.10
4         2011-03-21    0.86          0.50
4         2011-03-22    1.00          0.10

我需要根据公司 (sp100_id) 随着时间推移的平均看涨度 进入前 3 名:

SELECT 
  sp100_id, 
  AVG(bullishness) as bullishness, 
  AVG(agreement) AS agreement 
FROM stocks 
WHERE _date BETWEEN '2011-03-16' AND '2011-03-22' 
GROUP BY sp100_id LIMIT 3

这很好用，结果是

SP100_ID    BULLISHNESS AGREEMENT
2           2.038           0.658
4           1.564           0.366
3           0.996           0.866

现在我有了前 3 名，我需要根据 AGREEMENT 对前 3 名重新排序，升序:

SP100_ID    BULLISHNESS AGREEMENT
4           1.564           0.366
2           2.038           0.658
3           0.996           0.866

这可能与一个查询有关吗？我尝试了以下但没有用。它仍然只按看涨

排序

SELECT 
  sp100_id, 
  AVG(bullishness) as bullishness, 
  AVG(agreement) AS agreement 
FROM stocks 
WHERE _date BETWEEN '2011-03-16' AND '2011-03-22' 
GROUP BY sp100_id 
ORDER BY bullishness DESC, agreement ASC LIMIT 3

所以要清楚:(1) 我需要找到平均牛气度最高的前 3 家公司 (2) 然后需要从最低到最高的一致性对这 3 家公司进行排序。最好有一个查询。你知道怎么做吗？

Answer 1

它被称为结构化查询语言，因为您可以构建查询(又名虚拟表)嵌套在其他查询中的结构。

将您的第一个查询(除了它需要自己的 ORDER BY 子句外是正确的)并将其嵌套在另一个查询中，就像这样。

SELECT * 
  FROM (
           SELECT sp100_id,  
                  AVG(bullishness) as bullishness, 
                  AVG(agreement) AS agreement 
             FROM stocks 
            WHERE _date BETWEEN '2011-03-16' AND '2011-03-22' 
         GROUP BY sp100_id
         ORDER BY bullishness DESC
            LIMIT 3
  ) subquery
  ORDER BY agreement ASC

开始摆弄:http://sqlfiddle.com/#!2/c9ff0/7/0