Data Validation – Between Tables (1 Viewer)

[Cosmos75]

I have a Task and Sub Task Table (One Task to Many Sub-Task relationship)

Both the Task and Sub-Task have a Finish Date field.

I want to validate using Data Validation that Task Finish Date is equal (or not earlier than) to the last Sub Task Finish Date. Is there anyway to accomplish this?

 

[vangogh228]

Can you put this validation requirement in the Finish Date properties for the task? >=[Subtask Finish Date]

 

[Cosmos75]

vangogh228,

Didn't work, it said it couldn't find [Subtask Finish Date].

I used [tblSubTask]![Subtask Finish Date] .

 

[Pat Hartman]

In the BeforeUpdate event of the date field on the main form, use a DMax() function to find the max date for the related subtask records and compare the dates. You can cancel the update event if the date is incorrect.