README.md

Schema Relationships

Hatchify can help you define and build complex relationships between different models within your application. In our previous examples we have used Players and Teams to briefly describe a relationship. Lets take a look at that example again:

import { belongsTo, datetime, hasMany, string } from "@hatchifyjs/core"
import type { PartialSchema } from "@hatchifyjs/core"

export const Player = {
  name: "Player",
  attributes: {
    firstName: string(),
    lastName: string(),
    startDate: datetime(),
    endDate: datetime(),
  },
  relationships: {
    team: belongsTo("Team"),
  },
} satisfies PartialSchema

export const Team = {
  name: "Team",
  attributes: {
    name: string(),
  },
  relationships: {
    players: hasMany("Player"),
  },
} satisfies PartialSchema

We can see that the Player has a belongsTo property that names Team as the target. Similarly, the Team contains a hasMany property that names Player as the target. Given this description we can reason that a Team can have many players and each Player can belong to a single Team.

For another example lets look at Movies and Actors. Unlike Players and Teams an Actor CAN be in more than one Movie and a Movie can contain many Actors. How could we describe this sort of relationship?

import { belongsTo, string } from "@hatchifyjs/core"
import type { PartialSchema } from "@hatchifyjs/core"

export const Actor = {
  name: "Actor",
  attributes: {
    name: string(),
  },
  relationships: {
    movies: belongsTo("Movie").through(),
  },
} satisfies PartialSchema

export const Movie = {
  name: "Movie",
  attributes: {
    name: string(),
  },
  relationships: {
    actors: belongsTo("Actor").through(),
  },
} satisfies PartialSchema

In this scenario, both models have a many-to-many relationship using the hasMany().through() association. However, to define this complex relationship, we require an additional table. This table is created using the through option, where we specify a through Model named ActorMovies, resulting in a table named actor_movie.

For more information on these relationships and the options available check these out:

• Belongs To
• Has Many
• Has Many Through
• Has One