Question

在进行JOIN查询时，MySQL输出了DATE（）类型字段的0000-00-00，尽管在执行简单的SELECT（2017-03-02等）时值不为空。

SELECT * FROM t1
JOIN t1_t2 ON t1_t2.t1_id = t1.t1_id
JOIN t2 ON t1_t2.t2_id = t2.t2_id
WHERE t1_id = 52
ORDER BY t2.type, t1.my_date_field;

奇怪的是，当我向查询添加DATE_FORMAT（my_date_field）时，它可以工作：

SELECT *, DATE_FORMAT(`my_date_field`, "%Y-%m-%d")
(...)

我做了一个SQLFiddle http://sqlfiddle.com/#!9/23a965/8但无法复制问题

编辑问题来自ORDER BY子句，删除'ORDER BY release_date'“解决”了这个问题 - 但仍然没有在小提琴上复制。

Answer 1

我有两个选项让你尝试，考虑到你的问题听起来像是一个mysql bug。

选项1

SELECT *, DATE_FORMAT(alb.release_date, "%Y-%m-%d")
FROM artist art
JOIN track_artist_album taa  ON taa.artist_id = art.id
JOIN album alb ON alb.id = taa.album_id
JOIN track tra ON tra.id = taa.track_id
WHERE art.id = 1
ORDER BY tra.name, DATE_FORMAT(alb.release_date, "%Y-%m-%d");

选项2：

SELECT * FROM 
(
SELECT art.id as art_id, art.name as art_name, 
  alb.id as alb_id, alb.name as album_name, tra.id as tra_id, tra.name as tra_name, DATE_FORMAT(alb.release_date, "%Y-%m-%d") fmt_release_date
FROM artist art
JOIN track_artist_album taa  ON taa.artist_id = art.id
JOIN album alb ON alb.id = taa.album_id
JOIN track tra ON tra.id = taa.track_id
WHERE art.id = 1
) A
ORDER BY a.tra_name, a.fmt_release_date

DATE（）类型字段在JOIN查询中显示为0000-00-00

1 个答案: