Array of foriegn keys

[cheesycod]

It would nice if we could have a array with base_column of foreign keys

[dantownsend]

It's an interesting idea. I've never tried creating an array of foreign keys, so not sure what's possible.

[sinisaos]

@dantownsend This can already be used if we move ValueError check

piccolo/piccolo/columns/column_types.py

Lines 2613 to 2614 in 16276c6

	if isinstance(base_column, ForeignKey):
	raise ValueError("Arrays of ForeignKeys aren't allowed.")

After that the migrations work and we can add records by adding a primary key (without any checking!) to the base_column (Piccolo Admin works for adding a primary key (Serial, UUID), but we lost the FK select widget).
But should we implement this and what is it useful for? The Postgres documentation does not mention this option. Also, people advise using many-to-many relationships for this (which makes sense to me) for reasons nicely explained here. I think we should close this as not planned.