PostgreSQL如果缺少则使用上一行的值

尝试：

WITH t as (  SELECt time_series as trunc     FROM generate_series('2013-02-27 22:00'::timestamp, '2013-02-28 2:00',    '1 hour') as time_series)SELECt DISTINCT ON(t.trunc) t.trunc, e.id  FROM t  JOIN event e    ON e.created < t.trunc  ORDER BY t.trunc, e.created DESC

如果太慢-告诉我。我会给你一个更快的查询。