Validation to allow one decimal only

Question

I'm looking to validate percentage field type to ensure they contain only one decimal and can be between 0.0 and 100.0.I want to see an error message when more than one decimal is entered.

I tried this: NOT(REGEX(TEXT(ACC__c),"[0-9]{3}+(.[0-9]{1}?)?$"))

But not worked. Any tips would be appreciated.

Thanks

Answer 1

While creating the % field you can specify the number of decimal places. This is standard functionality.

Then you can have a simple validation

ACC__C < 0 || ACC__C > 1

To limit values between 0 to 100. Or you can have just this validation. That should also work. On UI, the number would be rounded off.

As noted by sfdcfox below, please check the rounding off for record created via API.

Answer 2

As a validation rule, you'd multiply by 1000 and round, then multiply by 10, and compare it to multiplying by 10000. If the results don't match, you have more than one decimal present.

ACC__c < 0 || ACC__c > 1 || (FLOOR(ACC__c * 1000) * 10 <> ACC__c * 10000)

This works by checking if the rounded version equals the unrounded version. If they don't match, we'll throw an error.

Note that Percent fields are stored in decimal notation, where 0 means 0% and 1 means 100%. For this reason, we compare the boundaries with 0 and 1.

Alternatively, as @Derek F pointed out, we can save a bunch of compiled size by using MOD:

Acc__c < 0 || Acc__c > 1 || MOD(Acc__c * 10000, 10) <> 0