Is nested link not supported?

[ratson]

edgedb version: 1.4+5ffe34

module default {
  type Link {
    multi link links -> Link {
      link another -> Link;
    }
  }
}

edgedb migration create gives the following error,

error: Unexpected 'another'
  ┌─ ./dbschema/default.esdl:4:12
  │
4 │       link another -> Link;
  │            ^^^^^^^ error

edgedb error: cannot proceed until .esdl files are fixed

The error is not explaining why it is failing.

Is this not a supported syntax?

[vpetrovykh]

You can only have properties attached to links (https://www.edgedb.com/docs/datamodel/links#link-properties). Links themselves have to be part of object types.

What are you trying to achieve with this "nested link" structure?

One way to define a nested structure is:

module default {
  type Link {
    multi link links -> Link;
    link another -> Link;
  }
}

Then you can query the nested structure like so:

select Link {
  links: {
    another
  }
}

Potentially you may want 2 different types, though:

module default {
  type Link0 {
    multi link links -> Link1;
  }

  type Link1 {
    link another -> Link0;
  }
}

[ratson]

@vpetrovykh Thank you for the answer.

The second solution is close to what I am looking for, here is my modified version.

module default {
  type Link {
    multi link links -> NestedLink;
  }

  type NestedLink extending Link {
     link another -> Link;
  }
}

Not optimal, but good enough.