Writing the GQL schema

We must write the GQL schema by using its type system. If we think first about our data, it will be easier to implement it. Let’s try to convert the following diagram to a schema:

Figure 14.2 – Data relation

The data relation in Figure 14.2 describes the entities and the relations between them:

• A family has multiple members
• A person may have numerous friends that are other family members

So, we can represent these entities into object types by writing the following Schema Definition Language (SDL):

type Family {
  id: ID!
  name: String!
  members: [Person!]!
}
type Person {
  id: ID!
  family: Family!
  fullName: String!
  nickName: String
  friends: [Person!]!
}

The syntax to define a GQL entity is easily readable. We have defined two types. Each type has a PascalCase name and a list of fields surrounded by curly...