Append query without duplication

[ChobeyGuddu]

HI All,
I am looking for solution to Append my query without duplication...

Actually, I have created a database which will be used by 10-15 employees, it has a data entry form where I have 2 dates :

1) Program Completion date
2) Rework on Program date

IF a Program Completion date is claimed (means entered), which means program is complete but in some cases we have to redo some work on the same program - so in that case I want to record my old data in another sheet before we start with rework on Program.

I thought it can be done by Append query to append existing data on new table with Query Criteria on Rework on Program date >=Date()
But every time someone, enter a Date in "Rework on Program date" - it will run a code and add the data to table - which means it will also add another data again which is entered on the same day for another Program...



Can you pls help me with the solution - I might be working on completely wrong direction... so pls guide me as well if that's the case.


Sample data: attached

[ranman256]

Make a query that pulls existing records.
You can make the append query that uses this query to only append the missing recs.
use an outer join to only get records that DONT exist in the target table.

[ChobeyGuddu]

Hi Ranman,
Thanks for response... but still unclear...

Created an Append query & running it when the criteria is true (basically its when rework date is entered on reworkonprogramdate).
I have created a Table (tblRework) and added fields which is require to append the data there...

To run the Append query I have added below code to reworkonProgramdate - after update event

Private Sub ReworkonProgramdate_AfterUpdate()
DoCmd.SetWarnings False
MsgBox ("(REWORK) - Copying Existing Record to another Sheet")
DoCmd.OpenQuery "REWORK", acNormal, acEdit
DoCmd.SetWarnings True
End Sub

But the issues are :
1) When more than 1 employees are accessing it and adding a rework date to it - it will run multiple time and create a duplicate entry on Append table (tblRework).
2) We know its running the query but its not appending data to the tblrework for some reason until i run it second time (manually).

Can you pls elaborate on these fronts pls ?

Thanks in advance,
Chobey Guddu