I would like to have in the League tables all of the seasons and divisions as you can see with data > seasons. I have set it up as I believe would work using @connection.

So the question is, how would I have to change my division schema so that divisions are included in the League.

I have spent a good time reading over @connections & @key and understand that when using the key a hash is created with the ID that I have given them. But I do not understand enough having read the connections documentation multiple times as to why this wouldn't work.

I would love to understand this better, so i am giving all I can to try to develop an understanding!

n.b I believe it is worth mentioning also, that each time I change my schema and the amplify mock rebuilds the hash keys, they get added. I wonder if this has some impact? Should I be cleaning the SQLite completely with each schema change when keys are involved?

League Schema

type League @model
{
  id: ID!
  name: String!
  faId: ID!
  logo: String
  seasons: [Season] @connection(keyName: "bySeason", fields: ["id"])
  division: [Division] @connection(keyName: "byDivision", fields: ["id"])
}

Seasons Schama

type Season @model @key(name: "bySeason", fields: ["leagueID"])
{
  id: ID!
  name: String!
  faId: ID!
  yearStart: AWSDate
  yearEnd: AWSDate
  leagueID: ID!
  league: League! @connection(fields: ["leagueID"])
  division: [Division] @connection(keyName: "byDivision", fields: ["id"])
}

Division Schema

type Division @model
@key(name: "byDivisionFromSeason", fields: ["leagueID" "name"])
@key(name: "byDivision", fields: ["seasonID", "leagueID"])
{
  id: ID!
  name: String!
  faId: ID!
  divisionSeasonFaId: String
  leagueID: ID!
  seasonID: ID!
  league: League! @connection(fields: ["leagueID"])
  season: Season! @connection(fields: ["seasonID"])
  teams: [TeamConnection] @connection(keyName: "byTeamDivision", fields: ["id"])
  games: [Game] @connection(keyName: "byGameForDivision", fields: ["id"])
  ageInput: String!
  level: Int!
}

Queries

  listLeagues {
    items {
      name
      division {
        items {
          name
        }
      }
      seasons {
        items {
          name
          division {
            items {
              name
            }
          }
        }
      }
    }
  }

Data

I have shown here that the structure is correct as the Seasons included in the League have the Divisions as expected

{
  "data": {
    "listLeagues": {
      "items": [
        {
          "name": "Southern Amateur League",
          "division": {
            "items": []
          },
          "seasons": {
            "items": [
              {
                "name": "2020-21",
                "division": {
                  "items": [
                    {
                      "name": "Junior Section Division 5B South"
                    },
                    {
                      "name": "Junior Section Division 4 South"
                    },
                    {
                      "name": "Intermediate Division 3"
                    },
                  ]
                }
              },
              {
                "name": "2019-20",
                "division": {
                  "items": []
                }
              },
            ]
          }
        }
      ]
    }
  }
}

Edit

Since reducing just the keys on division to seasonID and leagueID on each key, when clearing the data it appears to throw an unusual error. I had believed that return null on a @connection was perfectly valid?