{
  "name": "book",
  "fields": {
    "id": {
      "type": "unsigned long",
      "constraint": "primary_key"
    },
    "title": {
      "type": "string",
      "size": 511
    },
    "book_author": {
      "type": "author",
      "constraint": {
        "type": "foreign_key",
        "references": "id"
      }
    },
    "published_in": {
      "type": "unsigned_short"
    }
  }
}