Strange key column and duplicate behaviour

AppSheet AppSheet Q&A
1

I am trying to solve an issue of duplicate key in the table where data is recorded from forms with multiple users: Thanks to the help of this community, I have created a virtualcolumn with intial value DateTime NOW() & [username] which for me makes my key unique. It should be impossible for a user to open twice the same form at the same time.
But it is the case; Today I had a duplicate key “08/22/201912:07:11John”. How that can be ??

Thanks for your help.

2

You can’t use NOW() with the key column if it’s with virtual column. It will change the DataTIme value everytime when you sync the app. You should use normal column instead.

3

OK, Changed. But is this going to solve my problem of duplicates with this key (knowing that UNIQUEID() was causing me problem of duplicates as well ?

4

When you have this UNIQUEID() with an initial value and then use it with a key column, you won’t have duplicate records.