DateAdd function not working

[JackieFeng]

In my form, i have three fields: Start Time, End Time and Duration.

I try to calculate end time by add up start time and duration so i put DateAdd(n,Duration,StartTime) into the default value of end time. When i change the duration or starttime, the end time is not changed automatically.



What I did wrong??..

[ranman256]

the time interval parameter is a string:

DateAdd("n",Duration,StartTime)

[orange]

Show readers the real code you are using.
Review DateAdd
Check the format and syntax carefully.

Why do you need all three:
StartTime, EndTime and Duration

[JackieFeng]

The syntax is correct. I need start time and duration to calculate end time... Should i put the function into default value???..

[orange]

Show readers the code.


Please tell us more about this?????

Should i put the function into default value???

[JackieFeng]

[orange]

Are you working with EndTime or Finishing Time? Unclear.

In my form, i have three fields: Start Time, End Time and Duration.

If you have 3 fields in your table, you do not need all three. Do not store calculated fields/values.

How about posting a copy of the database in zip format?

[JackieFeng]

appointmenthelp.zip plz check my database

[JackieFeng]

i posted plz check

[orange]

Some comments:
-Every table should have a primary key. No PK on Booking or BookingHistory tables
-You should adopt a naming convention that does NOT allow embedded spaces.
-Date is a reserved word in Access.
-Finishing Time in tblBooking
-Finsihing Time in tblBookingHistory
-tblTreatment does not have a Start nor End/Finishing Time ---only Duration.

formBooking recordsource

SELECT tblBooking.[Booking ID], tblBooking.[Customer ID], tblBooking.[Therapist ID]
, tblBooking.[Treatment ID], tblBooking.[Room ID]
, tblBooking.Date, tblBooking.[Start Time], tblBooking.[Finishing Time], tblBooking.Completed
, tblTreatment.Duration FROM tblTreatment INNER JOIN tblBooking 
ON tblTreatment.[Treatment ID] = tblBooking.[Treatment ID];

[JackieFeng]

Thank you so much. Can you explain why do i need start time and finishing time in tbltreatment? Also can you explain why dateadd function not working in the booking form.

[orange]

??
Can you explain why do i need start time and finishing time in tbltreatment? I'm not saying you do. Your original post was about using DateAdd to determine/calculate a value. What you didn't tell us was that Starttime was in 1 table and Duration in another.

[JackieFeng]

so you mean starttime and duration must be in the same table?

[orange]

Step back, forget your specific issue.

If I said I have an appointment that starts at 12:15 today and lasts for 30 minutes. We're still talking about the same appointment, right? So they would typically be stored in the same table in database terms. The Duration is an attribute of this specific appointment.

[JackieFeng]

ok. I understand what you said.