I have been facing a strange scenario when comparing dates in postgresql(version 9.2.4 in windows).
I have a column in my table say update_date with type 'timestamp without timezone'.
Client can search over this field with only date (i.e: 2013-05-03) or date with time (i.e: 2013-05-03 12:20:00).
This column has the value as timestamp for all rows currently and have the same date part(2013-05-03) but difference in time part.
当我比较这篇专栏文章时，我得到了不同的结果.比如:
select * from table where update_date >= '2013-05-03' AND update_date <= '2013-05-03' -> No results
select * from table where update_date >= '2013-05-03' AND update_date < '2013-05-03' -> No results
select * from table where update_date >= '2013-05-03' AND update_date <= '2013-05-04' -> results found
select * from table where update_date >= '2013-05-03' -> results found
我的问题是如何让第一个查询能够得到结果，我的意思是为什么第三个查询能够工作，而第一个查询却不能？