我如何知道某个日期是否在特定时期内

Question

我们正在捕获某个表中的出勤数据,主要捕获值(userId,startDate,endDate).如果一个人离开应用在特定日期则只的startDate充满,如果他申请一组日期,则开始/结束日期被捕获.什么查询将帮助我找到一个人是否在某个特定日期休假(比如本月9日,12日,15日)

user1, 9/8/2010
user2, 9/9/2010, 9/10/2010
user3, 9/14/2010
user4, 9/15/2010
user5, 9/9/2010, 9/20/2010

users taking leaving on 9th would be user2, user5
users taking leaving on 12th would be user5
users taking leaving on 15th would be user4, user5

查询不应包含数据库特定的构造,它需要使用hibernate作为ORM层在h2/mysql/postgres上运行

Answer 1

SELECT  userId
FROM    mytable
WHERE   '2010-09-09' BETWEEN startDate AND COALESCE(endDate, startDate)