Polymorphic table references

[Meryldominguez]

Hello all! Apologies if this solution exists, I am rather new to flutter/dart/drift and still learning a ton.

I am trying to implement a polymorphic Tags table, and cannot find anything in the docs to suggest that is possible.

Ideally It could look something like this?

@TableIndex(name: 'tags_name', columns: {#name})
class Tags extends Table with Timestamps, AutoIncrementingPrimaryKey{

  TextColumn get name => text().withLength(min: 6, max: 32)();
}

class TagItem extends Table with Timestamps, AutoIncrementingPrimaryKey{
  IntColumn get tagId =>
      integer().nullable().references(Tags, #id)();
  IntColumn get itemId =>
      integer().nullable().references([Composers, People, Events], [#id, #id, #id])();
}

Is this in the works? already supported?

[simolus3]

There is no support for polymorphic relations between tables in drift. So you would have to manually add a "type" column to TagItem to describe whether the item references composers, people or events. That also means that you can't rely on the foreign key capabilities of sqlite3 for that reference.

I haven't heard of this feature before and I couldn't find too many other database libraries supporting it either. I'm not sure if drift should support this given that it's not supported by databases and requires rewriting queries at runtime.