我正在尝试这个查询
SELECT date_trunc('day', commit_at) AS day, count(*)
FROM commits
GROUP BY date_trunc('day', commit_at)
ORDER BY date_trunc('day', commit_at) ASC;
并且它返回
day | count
---------------------+-------
2015-05-18 00:00:00 | 5
2015-05-19 00:00:00 | 2
2015-05-21 00:00:00 | 2
(3 lignes)
问题是:如何强制空的日期也在结果中显示?
day | count
---------------------+-------
2015-05-18 00:00:00 | 5
2015-05-19 00:00:00 | 2
2015-05-20 00:00:00 | 0
2015-05-21 00:00:00 | 2
(3 lignes)
generate_series
函数。 - xQbert