Valid IF - based on a virtual column related to a specific date input

AppSheet AppSheet Q&A
1

Hello guys,
I’m trying to set a condition that doesn’t allow you to insert a date if another field related to that date already exists. I calculated the “year_month” field with a virtual column that return a date format in this way (for example 01/01/2025 switch in 01_January_2025)

Now, i would set a valid if condition that not allow to input a date IF is alredy exist the “year_month” related to this date.

Example. User input 02/01/2025 but in the table alredy exixst the virtual colum “year_month” with the value “01_January_2025” because another user input previously the date “01/01/2025”.

I hope to be clear.

thanks in advance!

2

Please try in the valid-if of the date column

ISBLANK(
FILTER(
“Table-Name”,
(TEXT([_THIS] , “YYYYYMM”)= TEXT([Date_Column], “YYYYYMM”))
)

  • LIST([_THISROW])
    )

Where [Date_Column] is the date columnin the table. I believe you may not need VC for this.

Please note that such duplicate prevention approaches can occasionally fail in a multi user environment.

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