Key with today()

[Olivia1]

Hello,

I want to create a reliable key and any columns can do date.

I want to do it by concatenate the date and the time of NOW() but it say that :

"The key column 'ID' of table 'Installation' is not a legal key because it contains an AppFormula whose value may change over time. We chose a new key for 'Installation'."

I try to take the day by "date(today())" but it's don't work and i think i'm wrong by this way.

My code is : concatenate(today(),[Ville],[Nom client],[Appareils],[Table])

Do you have any idea to resolve that?

it's possible to create a line which will registered the date when we enter a new line ?

Thanks you to read

[Marc_Dillon · Accepted solution]

Your original expression is fine, it's just that you need to use it in Initial Value instead of App Formula. Which is mostly explained by the error message "is not a legal key because it contains an AppFormula whose value may change over time"

Read here to further understand the difference:

https://help.appsheet.com/en/articles/961507-app-formulas-and-initial-values

I recommend using UNIQUEID() for a key value.

https://help.appsheet.com/en/articles/1023086-what-is-a-key

[Marc_Dillon · Accepted solution]

Your original expression is fine, it's just that you need to use it in Initial Value instead of App Formula. Which is mostly explained by the error message "is not a legal key because it contains an AppFormula whose value may change over time"

Read here to further understand the difference:

https://help.appsheet.com/en/articles/961507-app-formulas-and-initial-values

I recommend using UNIQUEID() for a key value.

https://help.appsheet.com/en/articles/1023086-what-is-a-key

[Olivia1]

I have the same error when i try to use uniqueid and i can't modify the type of the column ...

this is because it's a virtual column?

[Marc_Dillon]

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this is because it's a virtual column?

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Yes.

[Olivia1]

Do you know if it's possible to create a column which will do that in excel ? or do something to resolve this problem...?

[Marc_Dillon · Accepted solution]

1. Add a new real column to the sheet
2. Manually fill in unique values for all existing rows (I use the formula =DEC2HEX(RANDBETWEEN(0, 999999999), 8 ) , then copy and paste values only)
3. Regenerate Structure on the Table in the app editor
4. Set UNIQUEID() as Initial Value

[Olivia1]

Merci merci merci ! 😄 i understand now