entity-schema.md

Entity schema

Checkpoint requires a set of defined GraphQL Schema Objects. The schema objects will be used to create a database structure for indexing this data and also generating GraphQL Queries for accessing the indexed data.

In Checkpoint terms, these schema objects are called Entities, an Entity can be defined as a GraphQL Object with a unique name and an id field.

For example:

""" Vote is a valid entity """
type Vote {
  id: String!
  voter: User
  space: String
  proposal: Int
  choice: Int
  vp: Int
  created: Int
}

type User {
  id: String!
  vote_count: Int
  created: Int
}

Vote and User are valid entities because their names are unique (within the schema) and contain an id field.

Query generation

Checkpoint generates two Query fields for each of the defined entities. One for querying a single entity record by its id and the second for querying multiple records of an entity.

For example, using the earlier defined User entity, Checkpoint will generate two query fields like:

type Query {
  user(id: ID): User
  users(
    first: Int
    skip: Int
    orderBy: String
    orderDirection: OrderDirection
    where: WhereUser
  ): [User]
}

type WhereUser {
  id: String
  id_in: [String]
  vote_count_gt: Int
  vote_count_gte: Int
  vote_count_lt: Int
  vote_count_lte: Int
  vote_count: Int
  vote_count_in: [Int]
  created_gt: Int
  created_gte: Int
  created_lt: Int
  created_lte: Int
  created: Int
  created_in: [Int]
}

Things to note:

• The name of the single record entity query is derived from the entity's name lowercased.
• The name of the multi-record entity query is derived from the entity's name lowercased with an s suffix.
• The generated Where* types fields for multi-record are derived based on original fields in the entity, and non-null values are treated a AND where filters when being executed against the database.