Question

我想从2014-11-05 23:18:07.452957-07开始减去三个月。它应该提供类似2014-08-05 23:18:07.452957-07的输出我正在尝试这个：

 SELECT created_on, DATE (created_on - INTERVAL '5 months') FROM user_authentication_logs   
 WHERE user_id = 1014 ORDER BY created_on DESC LIMIT 1

但日期格式已更改。请帮忙。提前谢谢。

Answer 1

首先，只需删除Date广告：

SELECT created_on, DATE (created_on - INTERVAL '5 months') FROM user_authentication_logs   
 WHERE user_id = 1014 ORDER BY created_on DESC LIMIT 1

通过

SELECT created_on, created_on - INTERVAL '5 months' as created_on_minus_5_months FROM user_authentication_logs   
 WHERE user_id = 1014 ORDER BY created_on DESC LIMIT 1

因为Date类型仅包含日期（无时间）

如果您的日期格式输出已更改，您可以使用t_char功能

自定义它

Answer 2

试一试我想这就是你想要的

 SELECT created_on, cast((created_on - INTERVAL '5 months')as timestamp with time zone) FROM user_authentication_logs   
 WHERE user_id = 1014 ORDER BY created_on DESC LIMIT 1;

在postgres中减少日期（月）

2 个答案: