type Channel @model {
  id: ID!
  name: String!
  url: String!
  createdAt: String
  messages: [Message] @connection(keyName: "byChannel", fields: ["id"])

}

enum ModelSortDirection {
  ASC
  DESC
}

type Message @model(subscriptions: null)
@key(name: "byChannel", fields: ["channelId", "createdAt"], queryField: "listMessagesByChannel")
{
  id: ID!
  channelId: ID!
  username: String!
  content: String!
  createdAt: String
  channel: Channel @connection(fields: ["channelId"], sortField: "createdAt")
}

type Subscription {
  onCreateMessage(channelId: ID): Message @aws_subscribe(mutations: ["createMessage"])
}