MS ACCESS 2016中的SQL语言

Question

i need help with some query in MS ACCESS 2016 with SQL language. I have a table with 20 employers, and the table includes name, last name, gender, date of birth, date of employment and payment. I need to calculate specific age, I mean, I want to know who is for example 25 years old of my employers, i dont know how to write command in SQL language to calculate that, i would be very grateful if someone can help me.

Answer 1

You cannot calculate 100% correct age directly in SQL in a simple way.

So use an UDF (user defined function) like this:

Public Function AgeSimple( _
  ByVal datDateOfBirth As Date) _
  As Integer

' Returns the difference in full years from datDateOfBirth to current date.
'
' Calculates correctly for:
'   leap years
'   dates of 29. February
'   date/time values with embedded time values
'
' 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.
' After an idea of Markus G. Fischer.
'
' 2007-06-26. Cactus Data ApS, CPH.

  Dim datToday  As Date
  Dim intAge    As Integer
  Dim intYears  As Integer

  datToday = Date
  ' Find difference in calendar years.
  intYears = DateDiff("yyyy", datDateOfBirth, datToday)
  If intYears > 0 Then
    ' Decrease by 1 if current date is earlier than birthday of current year
    ' using DateDiff to ignore a time portion of datDateOfBirth.
    intAge = intYears - Abs(DateDiff("d", datToday, DateAdd("yyyy", intYears, datDateOfBirth)) > 0)
  End If

  AgeSimple = intAge

End Function

Copy and paste the code into an empty module.

Then run a query:

Select *, AgeSimple([DateOfBirth]) As Age
From YourTable
Where AgeSimple([DateOfBirth]) >= 25

Of course, replace table and field names with those of yours.