Unify all model fields to call get_prep_value from get_db_prep_value

[Julie Rymer]

Following on #34539, should all fields that do not currently call get_prep_value from get_db_prep_value be updated to call it so that we have no more inconsistency with the ​fields customization doc?

Here is the list of all concerned fieldst:

• AreaField (contrib.gis)
• DistanceField (contrib.gis)
• ArrayField (contrib.postgres)
• DurationField
• UUIDField (this one even has a definition for get_prep_value, but it is never called)
• ForeignKey (like previous one, possess definition for get_prep_value, never called)

Please give me your thoughts or if I missed anything.
I for one am in favour of harmonising all field to follow the field API

(PS: wasn't sure about what ticket type this should be classified as)

[Mariusz Felisiak]

I knew that it'd open Pandora's box 😞 IMO we gain anything from adding:

if not prepared:
    value = self.get_prep_value(value)

to all these fields, but the community can decide otherwise. We have to be very carefully with ForeignKey which has many subclasses.

• UUIDField (this one even has a definition for get_prep_value, but it is never called)

That's not true, see a ​coverage report.

• ForeignKey (like previous one, possess definition for get_prep_value, never called)

That's not true, see a ​coverage report.

[Mariusz Felisiak]

Related ​discussion on the forum.

[Shaheed Haque]

Please see #34644 for a possible regression caused by #34539.

(edit, nevermind, I see that has been closed)

[Mariusz Felisiak]

Tentatively accepted, but for concrete clases not as a rule. IMO, we definitely shouldn't do this for ForeignKey and its subclasses.