MS Access - Date after fourth birthday

问题

Hopefully a relatively simple query.

I'm using MS Access, I'm trying to work out from the date of birth, the 1st of September after their 4th birthday.

So if my DOB was 02/07/2015, it would return 01/09/2019.

If my DOB was 03/09/2015, it would return 01/09/2020.

Any help would be much appreciated.

Thanks

回答1:

You could define a function such as:

Function SchoolStart(dob As Date) As Date
    If DateSerial(Year(dob), 9, 1) < dob Then
        SchoolStart = DateSerial(Year(dob) + 5, 9, 1)
    Else
        SchoolStart = DateSerial(Year(dob) + 4, 9, 1)
    End If
End Function

Example:

?SchoolStart(#2015-07-02#)
01/09/2019 

?SchoolStart(#2015-09-02#)
01/09/2020 

Note that, with the current function logic, a birthday on the 1st September includes the child in that year's school intake:

?SchoolStart(#2015-09-01#)
01/09/2019 

---

Or, if you want to use the above logic directly in a query or control source for a form, you could use the following inline expression:

DateSerial(Year([YourDate])+IIf(DateSerial(Year([YourDate]),9,1)<[YourDate],5,4),9,1)

Here, [YourDate] is the field which contains the date on which the calculation is to be performed.

来源：https://stackoverflow.com/questions/53573388/ms-access-date-after-fourth-birthday