Tables that relate to themselves

[mitswan]

I have noticed tables that reference themselves will only work one way with this plugin.

In the example scenario, you can nested insert Child -> Parent OR Parent -> Child

create table app.parent (
  id serial primary key,
  name text not null
);

create table app.child (
  id serial primary key,
  parent_id integer,
  name text not null,
  constraint child_parent_fkey foreign key (parent_id)
    references app.parent (id)
);

But if you make it a single person table it will only let you nested insert Child -> Parent

create table app.person (
  id serial primary key,
  parent_id integer,
  name text not null,
  constraint person_parent_fkey foreign key (parent_id)
    references app.person(id)
);

[wafokevin]

I am facing the same problem, it must come from an inflection issue, I'll try to look into it.

[Eldow]

I digged a little bit into this.
I modified the package with https://www.npmjs.com/package/patch-package.
Inside PostgraphileNestedTypesPlugin l.177, I modified the isForward condition. It was masking some reverse relations when their constraints were related to themselves, eg :
const isForward = constraint.classId === table.id
I switched it to :
const isForward = constraint.classId === table.id && constraint.classId !== constraint.foreignClassId;
To allow these special kind of constraints to work.

Untested, use at your own risk.

I would be glad to make a PR but the repo owner doesn't seem to be maintaining it.

[mlipscombe]

Sorry for the delay. Changing the test for isForward just swaps the problem around -- you now get the the parent > child nested mutation, but lose the child > parent nested mutation. To fix this properly needs a bit of a refactor of the code I think. I've added a test for the currently working direction (child > parent), and I'll do some refactoring to make the other direction work right.