vyegorov

要获得所需的结果,首先需要找到每个公司的最后时间戳和紧挨着最后的时间戳。下面的查询非常简单:

SELECT c.company, c.mts, max(l.ts) AS lts
  FROM (SELECT company, max(ts) AS mts FROM cq GROUP BY company) AS c
  LEFT JOIN cq l
    ON c.company = l.company AND c.mts > l.ts
 GROUP BY c.company, c.mts;

现在您必须将此子查询与原始表联接以获得所需的结果:

SELECT c.company, l.quote, coalesce(l1.quote, 0),
       (l.quote - coalesce(l1.quote, 0)) AS result
  FROM (SELECT c.company, c.mts, max(l.ts) AS lts
      FROM (SELECT company, max(ts) AS mts FROM cq GROUP BY company) AS c
      LEFT JOIN cq l
        ON c.company = l.company AND c.mts > l.ts
     GROUP BY c.company, c.mts) AS c
  LEFT JOIN cq AS l ON l.company = c.company AND l.ts = c.mts
  LEFT JOIN cq AS l1 ON l1.company = c.company AND l1.ts = c.lts;

你可以在 SQL Fiddle .

这个查询只使用标准的sql功能,应该可以在任何rdbms上运行。