Question

下午好会员，我想在数据库中查看生日

使用函数

提供以下信息

class person

public property dateofbirth as nullable(of datetime)

end class


public function allperson() as Ienumrable(of preson) implements databank.allpersons

return _contact.values.oftype(of person).orderby(function(c) c.name)

end function




   public function birthday (startdate as date, Enddate as date) as IEnumerable (of Person) Implements databank.birthdaybetween


/.... ???

    end function

这是我的问题的图片 http://s8.postimg.org/vn4ufpmqt/problem.png

感谢 ELISA

Answer 1

假设生日函数应该返回所有在startdate和enddate之间的时间范围内庆祝生日的人，以下查询应该有效：

    Return (From x In allperson() _
        Where x.DateOfBirth.HasValue AndAlso x.DateOfBirth.Value.Year <= startdate.Year 
            AndAlso ((startdate.Month = x.DateOfBirth.Value.Month AndAlso startdate.Day <= x.DateOfBirth.Value.Day) _
               OrElse (startdate.Month < x.DateOfBirth.Value.Month)) _
            AndAlso ((x.DateOfBirth.Value.Month = enddate.Month AndAlso x.DateOfBirth.Value.Day <= enddate.Day) _
               OrElse x.DateOfBirth.Value.Month < enddate.Month)).AsEnumerable()

在日期范围vb.net期间发生的生日或周年纪念日

1 个答案: