33.3 The schema

Every exposed node type gets a GraphQL type and two root fields on Query:

one that fetches a node by id, such as event(id: ID!);
one that returns a page of nodes, such as events(filter, search, orderBy, descending, page, pageSize, ids).

Every node type implements the Node interface and its four system fields: id (the node's Guid), displayName, createdUtc and changedUtc. Here is the schema of the endpoint above, trimmed:

type Query {
  event(id: ID!): Event
  events(filter: EventFilterInput, search: String, orderBy: EventOrderBy, descending: Boolean = false,
         page: Int = 0, pageSize: Int, ids: [ID!]): EventResult!
  venue(id: ID!): Venue
  venues(filter: VenueFilterInput, search: String, orderBy: VenueOrderBy, descending: Boolean = false,
         page: Int = 0, pageSize: Int, ids: [ID!]): VenueResult!
  upcoming(filter: EventFilterInput, search: String, orderBy: EventOrderBy, descending: Boolean = false,
           page: Int = 0, pageSize: Int, ids: [ID!]): EventResult!
}

interface Event implements Node {
  id: ID!
  displayName: String
  createdUtc: DateTime!
  changedUtc: DateTime!
  price: Decimal!
  starts: DateTime!
  status: EventStatus!
  title: String
  venue: Venue
}

type EventNode implements Node & Event { ... }   # the same fields

interface Venue implements Node {
  ...
  capacity: Int!
  events(top: Int): [Event!]!
  location: GeoCoordinate
  name: String
}

type EventResult {
  items: [Event!]!
  totalCount: Int!
  pageIndex: Int!
  pageSize: Int
  durationMs: Float!
}

enum EventOrderBy { price starts status title }
enum EventStatus { Draft Published SoldOut Cancelled }

input EventFilterInput {
  price: DecimalFilterInput
  starts: DateTimeFilterInput
  status: EventStatusFilterInput
  title: StringFilterInput
  venue: RelatedNodeFilterInput
  and: [EventFilterInput!]
  or: [EventFilterInput!]
  not: EventFilterInput
}

Names. By default, names follow GraphQL conventions. With exactNames, the datamodel's names are used as they are:

	Default	With `exactNames`
Type	`Article`	`Article`
Field	`title`	`Title`
Root fields	`article`, `articles`	`Article`, `Articles`
Mutations	`createArticle`, …	`CreateArticle`, …

System fields keep their names. A property that would clash with one gets Value added: DisplayName becomes displayNameValue.
A name that is taken gets _2 added, with a warning.
An inherited property keeps the field name its base type gives it. A different name set on the subtype is ignored, with a warning.

Interfaces. A datamodel interface becomes a GraphQL interface, plus an object type for the nodes created as that interface (db.Create<IEvent>()), since GraphQL values cannot have an interface type. The object type drops the leading I (IEvent gives Event), or adds Node when it cannot (Event gives EventNode). Queries use the interface name; __typename returns the object type.

A class with exposed subclasses also gets an interface, <Class>Interface, so a field of the class's type can return subclass nodes. Read a subclass's own fields with ... on Subclass { }. A node of a type the endpoint does not expose is shown as its nearest exposed ancestor.

How properties map:

Datamodel property	GraphQL field	`filter` operators	In `orderBy`	Mutation input
`bool`	`Boolean!`	`eq` `ne`	yes	`Boolean`
`int`	`Int!`	`eq` `ne` `gt` `gte` `lt` `lte` `in` `nin`	yes	`Int`
enum (`int` with an enum type)	the enum, by name	`eq` `ne` `in` `nin`	yes	the enum
`long`	`Long!`	as `int`	yes	`Long`
`double`, `float`	`Float!`	as `int`	yes	`Float`
`decimal`	`Decimal!`	as `int`	yes	`Decimal`
`string`	`String`	`eq` `ne` `in` `nin`	yes	`String`
`DateTime`, `DateTimeOffset`	`DateTime!`, an ISO-8601 UTC string	`eq` `ne` `gt` `gte` `lt` `lte`	yes	`DateTime`
`TimeSpan`	`String!`	–	–	`String`, such as `"01:30:00"`
`Guid`	`ID!`	`eq` `ne` `in` `nin`	–	`ID`
`string[]`, `Guid[]`, enum `[]`	`[String!]!`, `[ID!]!`, `[Enum!]!`	–	–	a list
`GeoCoordinate`	`GeoCoordinate { latitude longitude }`, null when unset	–	–	`GeoCoordinateInput`
`FileValue`	`FileInfo { name size width height contentType url }`, null when empty	–	–	–
relation, "one" side	the related type	`eq` `in` (by id)	–	`ID`
relation, "many" side	`[T!]!` with a `top` argument	`eq` `in` (by id)	–	`[ID!]`, which replaces the whole set
`Reference<T>`	`T`	`eq` `in` (by id)	–	`ID`
`References<T>`	`[T!]!` with a `top` argument	–	–	`[ID!]`
`Embedded`, `EmbeddedMap`, `byte[]`, `float[]`, `object`	left out

A relation or reference to a type the endpoint does not expose is left out, with a warning in the Selected mode. Its filter stays, since it takes only an id.