ms-access-2016 - 访问 2016 公式

Question

最近学习访问，但发现自己对一个特定的公式很烂。我一直在尝试找到一种方法来计算自员工入职日期以来的年数以及代替今天的特定日期。我搜索并尝试了一些 Datediff 和 DATEDIF 没有运气，如果有的话，只会得到否定的结果。任何帮助是极大的赞赏。

Answer 1

那是因为它不是那么容易，而且有一些陷阱，如果你想正确计算闰年的话。

诀窍是始终在此函数中使用DateAdd ：

Public Function Years( _
  ByVal datDate1 As Date, _
  ByVal datDate2 As Date, _
  Optional ByVal booLinear As Boolean) _
  As Integer

' Returns the difference in full years between datDate1 and datDate2.
'
' Calculates correctly for:
'   negative differences
'   leap years
'   dates of 29. February
'   date/time values with embedded time values
'   negative date/time values (prior to 1899-12-29)
'
' Optionally returns negative counts rounded down to provide a
' linear sequence of year counts.
' For a given datDate1, if datDate2 is decreased step wise one year from
' returning a positive count to returning a negative count, one or two
' occurrences of count zero will be returned.
' If booLinear is False, the sequence will be:
'   3, 2, 1, 0,  0, -1, -2
' If booLinear is True, the sequence will be:
'   3, 2, 1, 0, -1, -2, -3
'
' If booLinear is False, reversing datDate1 and datDate2 will return
' results of same absolute Value, only the sign will change.
' This behaviour mimics that of Fix().
' If booLinear is True, reversing datDate1 and datDate2 will return
' results where the negative count is offset by -1.
' This behaviour mimics that of Int().

' DateAdd() is used for check for month end of February as it correctly
' returns Feb. 28. when adding a count of years to dates of Feb. 29.
' when the resulting year is a common year.
'
' 2007-06-22. Gustav Brock, Cactus Data, CPH.

  Dim intDiff   As Integer
  Dim intSign   As Integer
  Dim intYears  As Integer

  ' Find difference in calendar years.
  intYears = DateDiff("yyyy", datDate1, datDate2)
  ' For positive resp. negative intervals, check if the second date
  ' falls before, on, or after the crossing date for a full 12 months period
  ' while at the same time correcting for February 29. of leap years.
  If DateDiff("d", datDate1, datDate2) > 0 Then
    intSign = Sgn(DateDiff("d", DateAdd("yyyy", intYears, datDate1), datDate2))
    intDiff = Abs(intSign < 0)
  Else
    intSign = Sgn(DateDiff("d", DateAdd("yyyy", -intYears, datDate2), datDate1))
    If intSign <> 0 Then
      ' Offset negative count of years to continuous sequence if requested.
      intDiff = Abs(booLinear)
    End If
    intDiff = intDiff - Abs(intSign < 0)
  End If

  ' Return count of years as count of full 12 months periods.
  Years = intYears - intDiff

End Function

典型用法：

HiredYears = Years([HireDate], #12/31/2017#)

请注意，对于在一个月 1 日雇用的人，一整年的工作将在该月的下一个 1 日计算，因此表达式可能是：

HiredYears = Years([HireDate], #1/1/2018#)