当我通过created_at(时间戳)进行排序并限制结果数时,我的postgresql数据库保持返回相同的最后一行。每当我按时间戳排序时返回相同的行
最后的结果始终是同一行。看看这些结果中的最后一个ID:
looked=# select id,created_at from businesses order by created_at asc limit 2;
id | created_at
----+-------------------------------
38 | 2011-04-30 18:31:23.923475+10
20 | 2011-04-30 18:31:23.923475+10
(2 rows)
looked=# select id,created_at from businesses order by created_at asc limit 5;
id | created_at
------+-------------------------------
38 | 2011-04-30 18:31:23.923475+10
436 | 2011-04-30 18:31:23.923475+10
1334 | 2011-04-30 18:31:23.923475+10
2845 | 2011-04-30 18:31:23.923475+10
20 | 2011-04-30 18:31:23.923475+10
(5 rows)
looked=# select id,created_at from businesses order by created_at asc limit 10;
id | created_at
------+-------------------------------
38 | 2011-04-30 18:31:23.923475+10
436 | 2011-04-30 18:31:23.923475+10
1334 | 2011-04-30 18:31:23.923475+10
2845 | 2011-04-30 18:31:23.923475+10
3381 | 2011-04-30 18:31:23.923475+10
1089 | 2011-04-30 18:31:23.923475+10
822 | 2011-04-30 18:31:23.923475+10
2310 | 2011-04-30 18:31:23.923475+10
1773 | 2011-04-30 18:31:23.923475+10
20 | 2011-04-30 18:31:23.923475+10
(10 rows)
...和问题? – gbn 2011-04-30 09:49:47
所有created_at都一样! – Nighil 2011-04-30 09:57:22
这些值是相同的,因为它是我的种子数据,并且我选择将所有created_at值设置为NOW()。有没有更好的办法? – 2011-04-30 10:13:09