do not allow sending repeated values

[ADEFE_EUROPA]

how to create a condition where appsheets doesn't allow sending repeated values

[TeeSee1]

We all need more info to clarify your ask..

Email? Do not want send the same row in a table twice via a bot?

(in such a case creating an "email sent status" col should enable you to control the action..)

[WillowMobileSys]

I'll assume you mean submitting duplicate values.  There are 2 main ways to prevent duplicates

1)  If you have a list of values in a dropdown and want each to be chosen only once, then you can adjust the Valid_If expression that creates the list to remove values already chosen. 

2)  You can use Valid_If to also validate a value inserted.  In this case the expression returns Yes/No value.  You can insert an expression that checks to see if the value has already been inserted and only allow those that are new.

[ADEFE_EUROPA]

hoooooo thanks so much for the information! That's really what I'm
needing. But I believe it is something more complex: - I need the system
to analyze three variables together:

1. The same $ value;
2. The same person's name;
3. The same date;

I need the system to prevent a user from launching a form twice with these
combined values.

[WillowMobileSys]

You can use AND() inside of the expressions to combined multiple criteria.  Note that since the users will be entering 3 different values, you should choose one of them to perform the validation - the one most likely to be filled in last.  You can add to it that it only checks the validation if ALL 3 fields are filled - i.e ISNOTBLANK().

Also, since you need these 3 fields to validate for duplicates, all 3 should be required.

Some articles that might help:

https://help.appsheet.com/en/articles/2347624-and

https://help.appsheet.com/en/articles/2357267-isnotblank

https://help.appsheet.com/en/articles/2357314-select

https://help.appsheet.com/en/articles/1135911-conditional-expressions

[ADEFE_EUROPA]

I don't know how to explain it well:

I think I'm beginning to understand:
I need the system not to allow the completion of a form, when my table already contains the three values selected in this new form.
Example:
- Name: xxx
- Date: 01-02-2022
- Value: 1000.00

If the three values already appear in a row, do not allow the form to be sent!

No se se me explico bien:

Creo que que estoy empezando a compreender:
Necesito que el sistema no permita finalizar un formulário, cuando em mi tabla ya conste los tres valores selecionados en este nuevo formulário.
Ejemplo:
- Nombre: xxx
- Fecha: 01-02-2022
- Valor: 1000,00

Si los tres valores ya constan en una fila, no permita enviar el formulário!

[WillowMobileSys]

Yes, it might help to look over this article:

https://help.appsheet.com/en/articles/961211-valid_if-column-constraint