I have the following model defined:

import db from "../connection.js";
import objection from "objection";
const { Model } = objection;

Model.knex(db);

class User extends Model {
  static get tableName() {
    return "users";
  }

  static get relationMappings() {
    return {
      emails: {
        relation: Model.HasManyRelation,
        modelClass: Email,
        join: {
          from: "users.id",
          to: "emails.user_id",
        }
      }
    }
  }
}

class Email extends Model {
  static get tableName() {
    return "emails";
  }

  static get relationMappings() {
    return {
      user: {
        relation: Model.BelongsToOneRelation,
        modelClass: User,
        join: {
          from: "emails.user_id",
          to: "users.id",
        },
      },
    };
  }
}

And to query a User with their email addresses would require withGraphFetched() to be explicitly run every time as:

const myUser = await User.query().withGraphFetched("emails").findById(1)

I haven't been able to figure out what to write in the Model definition to make this possible, and I don't see any such examples online. Is it possible to ALWAYS have withGraphFetched("emails") automatically included in the query so it doesn't have to be explicitly written out every time?

I have the following model defined:

import db from "../connection.js";
import objection from "objection";
const { Model } = objection;

Model.knex(db);

class User extends Model {
  static get tableName() {
    return "users";
  }

  static get relationMappings() {
    return {
      emails: {
        relation: Model.HasManyRelation,
        modelClass: Email,
        join: {
          from: "users.id",
          to: "emails.user_id",
        }
      }
    }
  }
}

class Email extends Model {
  static get tableName() {
    return "emails";
  }

  static get relationMappings() {
    return {
      user: {
        relation: Model.BelongsToOneRelation,
        modelClass: User,
        join: {
          from: "emails.user_id",
          to: "users.id",
        },
      },
    };
  }
}

And to query a User with their email addresses would require withGraphFetched() to be explicitly run every time as:

const myUser = await User.query().withGraphFetched("emails").findById(1)

I haven't been able to figure out what to write in the Model definition to make this possible, and I don't see any such examples online. Is it possible to ALWAYS have withGraphFetched("emails") automatically included in the query so it doesn't have to be explicitly written out every time?

• javascript
• node.js
• knex.js
• objection.js

Share Improve this question Follow edited Mar 4, 2021 at 10:39 Rashomon 6,81244 gold badges3939 silver badges8080 bronze badges asked Apr 30, 2020 at 3:56 RajRaj 1,6652121 silver badges3232 bronze badges

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1 Answer 1

Sorted by: Reset to default 4

Such thing doesnt exist. Maybe you could create the logic in the beforeFind hook adding the eager loader to the knex instance, but it could generate a lot of undesired and strange side-effects.

The normal practice is adding a method to that specific case:

class User extends Model {
  static get tableName() {
    return "users";
  }

  static get relationMappings() {
    return {
      emails: {
        relation: Model.HasManyRelation,
        modelClass: Email,
        join: {
          from: "users.id",
          to: "emails.user_id",
        }
      }
    }
  }

  static async getUser (id) { // Or maybe getUserWithEmails
      return await this.query().withGraphFetched("emails").findById(id)
  }
}

Then you can just:

const myUser = await User.getUser(id)