How to Prevent Duplicate Records

[wael]

valid if today to monthly on not Duplicate

I want to prevent the Duplication of the [code] field, provided that it does not More than once during the month

This is what I got to not repeat the same day, please help me from not repeating during the month

NOT(IN([_THIS].[code], SELECT(Requests[code],
[Request Date] = TODAY()

)))

[Suvrutt_Gurjar]

Please create a VC called say [CodenMonth] with an expression something like CONCATENATE([code],"-",MONTH([Request Date])

Then your Valid_if in the [Code] column can be 

ISBLANK(
FILTER(
"Requests",
([_THIS] =[CodenMonth])
)
- LIST([_THISROW])
)

Please take a look at the last section of the article below on expression to detect duplicates. through valid_if

List expressions - AppSheet Help

Please post such questions in "Q&A" category.

[wael]

The code not work 

CONCATENATE([code],"-",MONTH([Request Date])

[Suvrutt_Gurjar]

Please share details of what you mean by not work(ing) and where you tried it.

[wael]

Please create a VC called say [CodenMonth] with an expression something like CONCATENATE([code],"-",MONTH([Request Date])

Then your Valid_if in the [Code] column can be 

ISBLANK(
FILTER(
"Requests",
([_THIS] =[CodenMonth])
)
- LIST([_THISROW])
)

Code  Error

valid if today to monthly on not 

I want to prevent the Duplication of the [code] field, provided that it does not More than once during the month

This is what I got to not repeat the same day, please help me from not repeating during the month

NOT(IN([_THIS].[code], SELECT(Requests[code],
[Request Date] = TODAY()

)))

[Suvrutt_Gurjar]

Please create a VC called say [CodenMonth] with an expression something like CONCATENATE([code],"-",MONTH([Request Date])

Please try  Valid_if in the [Code] column 

ISBLANK(
FILTER(
"Requests",
([_THISROW]. [CodenMonth]=[CodenMonth])
)
- LIST([_THISROW])
)

[wael]

Code  Error

[Suvrutt_Gurjar]

Please make the column type [CodenMonth] as text type

[wael]

Please make the column type [CodenMonth] as text type

OK

[wael]

I need this in a way, but an allowance on the same day is from the first day of the month to the day of registration

I reached disallowance on the same day as the request