Question: Why are Unique Dates a forbidden DocField?

1

While creating a new DocField, I marked the ‘Unique’ checkbox. But the DocType would not save, due to this error:

“Fieldtype Date for MyDateField cannot be unique”:

So I checked the Frappe code in doctype.py. Apparently only 3 types can be made unique:

  • Data
  • Link
  • Read Only

To keep making progress on my project, I’m going to edit the Frappe code, and allow for Dates.

But does anyone know/remember the reasoning behind this limitation?

~Brian

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2

What happens if you create two documents of the same doctype in the same day ?

Why would you want to make date unique ?

3

Would adding code in validate hook of the document to identify unique violations be an alternative to editing Frappe code?

4

@olamide_shodunke This isn’t a Creation Date. It’s just a custom field I added, of type = Date, that must be unique for all records in the table.

@aakvatech
Sure, that’s an alternative way of enforcing uniqueness.

This was intended as a “why” thread. That perhaps someone knew a good reason why this limitation exists in the current code.

I normally don’t ask “why” questions, because it’s extremely rare that anyone has the answer.
But I was feeling lucky yesterday. :slight_smile:

1 Like
5

Your date field is a custom field means it’s only you are using it for your specific purpose and maybe in a specific doctype.

So I believe because date as DocField in general would be too risky to be made unique for the reason @olamide_shodunke said.
And interesting to see if you change the code in frappe, what happen to the all other doctypes using date field.

6

None of the other Date fields have their ‘Unique’ checkbox marked. Because it’s forbidden.
So nothing should happen.

SELECT * FROM tabDocField
WHERE
    fieldtype = 'Date' AND `unique` = 1

-- No Results
7

You’re right.
Maybe if the other ‘Unique’ checkbox is accidentally checked then problem may arise.