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Has Many Through

One to Many Relationships​

One to Many​

The "has-many-through" relationship provides a convenient way to access distant relations via an intermediate relation. For example, let's assume we are building a deployment platform. A Project model might access many Deployment models through an intermediate Environment model. Using this example, you could easily gather all deployments for a given project. Let's look at the collections required to define this relationship:

projects
  _id - ObjectId
  name - string

environments
  _id - ObjectId
  projectId - ObjectId
  name - string

deployments
  _id - ObjectId
  environmentId - ObjectId
  commitHash - string

Now that we have examined the collection structure for the relationship, let's define the relationship on the Project model:

import { Mongoloquent } from "mongoloquent";
import Environment from "./yourPath/Environment";
import Deployment from "./yourPath/Deployment";

class Project extends Mongoloquent {
	static collection = "projects";

	static deployments() {
		return this.hasManyThrough(
			Deployment,
			Environment,
			"projectId",
			"environmentId"
		);
	}
}

The first argument passed to the hasManyThrough method is the name of the final model we wish to access, while the second argument is the name of the intermediate model.

import Project from "./yourPath/Project";

const project = await Project.with("deployments").find(
	"65ab7e3d05d58a1ad246ee87"
);

// your relationship data can accessed in the data property
console.log(project.data);

Monggoloquent can also select or exclude certain related model keys

import Project from "./yourPath/Project";

// with select keys
await Project.with("deployments", {
	select: ["commitHash"],
}).find("65ab7e3d05d58a1ad246ee87");

// with exclude keys
await Project.with("deployments", {
	exclude: ["commitHash"],
}).find("65ab7e3d05d58a1ad246ee87");

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