Dobby

# Defining Models

Models essentially describe a GraphQL type with its fields and relationships. Once defined, the model can be used to perform complex queries.

When defining a model, it's important to specify its entity name. However, this is not necessary if your bundler is configured to not minify class names.

Take this User model as an example

import { Model } from "@moirei/dobby";

class User extends Model {
  static entity = 'User';

  static fields(f) {
    ...
    f.id()
    f.string('name')
    f.string('email')
    f.json('meta', { watch: true })
  }
}

Its fields are id, name and email. Building queries will always ensure only the defined fields are selected.

const query = User.select(["id", "name", "email_verified"]);
const selects = query.getSelects(); // returns ["id", "name"]

# Relationships

You can define multiple models as related.

Consider the below definitions for this GraphQL demo (opens new window).

class User extends Model {
  static entity = "User";

  static fields(f) {
    f.id();
    f.string("name");
    f.string("email");
    f.model("posts", Post).list();
    f.model("comments", { type: Comment, default: [] });
  }
}

class Post extends Model {
  static entity = "Post";

  static fields(f) {
    f.id();
    f.string("title");
    f.string("body");
    f.boolean("published");
    f.model("author", User);
    f.list.model("comments", Comment);
  }

  static hooks() {
    return {
      findMany: findManyHook,
    };
  }
}

class Comment extends Model {
  // eager load author
  static queryRelationships: string[] = ["author"];

  static fields(f) {
    f.id();
    f.string("text");
    f.model("post", Post);
    f.model("author", User);
  }
}

const client = new Client({
  url: "https://graphql-demo.mead.io",
});

client.register(User, Post, Comment);

Note that providing array as default will automatically make the field a list

Now users can be retrieved with

const users = await User.findMany();

This by default will not include the users' posts and comments. To include these, use the include method of the Query Builder

const users = await User.select("id", "name")
  .include("posts", ["id", "title"])
  .include("comments")
  .findMany();

Since Comment model eagerly loads author, this will execute the following query

query {
  users {
    id
    name
    posts {
      id
      title
    }
    comments {
      id
      text
      author {
        id
        name
        email
      }
    }
  }
}

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