I don't understand this error : "SequelizeEagerLoadingError"

Issue

When I test my route with postman I have this error : "SequelizeEagerLoadingError"

I have tried to create an extra-setup for my foreign key because I found this solution (https://forum.freecodecamp.org/t/nodejs-sequelize-eager-loading-error/480312/7) but the problem is similar.

controllers/post.js :

exports.getAllPost = (req, res, next) => {
    /*** on récupère tous les posts ***/
    Post.findAll({
            include: [{
                model: User,
                attributes: ['username']
            }],
        })
        /*** si tout est ok ***/
        .then(post => res.status(200).json({
            post
        }))
        /*** sinon on envoie une erreur ***/
        .catch(error => res.status(400).json({
            error,
        }))

};

models/index.js :

require('dotenv').config();
const dbConfig = require("../config/db.config.js");
const Sequelize = require("sequelize");
const { applyExtraSetup } = require('./extra-setup');

const sequelize = new Sequelize(dbConfig.DB, dbConfig.USER, dbConfig.PASSWORD, {
  host: dbConfig.HOST,
  dialect: dbConfig.dialect,
  operatorsAliases: false,
  pool: {
    max: dbConfig.pool.max,
    min: dbConfig.pool.min,
    acquire: dbConfig.pool.acquire,
    idle: dbConfig.pool.idle
  }
});
const db = {};
db.Sequelize = Sequelize;
db.sequelize = sequelize;

db.users = require("./user.js")(sequelize, Sequelize);
db.posts = require("./post.js")(sequelize, Sequelize);
db.comments = require("./comment.js")(sequelize, Sequelize);

applyExtraSetup(sequelize);

module.exports = db;

models/post.js :

module.exports = (sequelize, Sequelize) => {
    const Post = sequelize.define(
      "post", {
        userId: {
          type: Sequelize.INTEGER
        },
        title: {
          type: Sequelize.STRING(40)
        },
      },     
    );
    return Post;
  };

models/extra-setup.js :

function applyExtraSetup(sequelize) {
    const { user, post, comment} = sequelize.models;

      user.hasMany(post, {
        foreignKey : 'userId',
        targetKey: 'id'
      });
      
      post.hasMany(comment, {
        foreignKey : 'postId',
        targetKey: 'id'
      });
      
      user.hasMany(comment, {
        foreignKey : 'userId',
        targetKey: 'id'
      });
}

module.exports = { applyExtraSetup };

Solution

In order to get posts along with users as an associated models you need define an association from post model to user model:

user.hasMany(post, {
        foreignKey : 'userId',
        targetKey: 'id'
      });
post.belongsTo(user, {
        foreignKey : 'userId',
        targetKey: 'id'
      });

Answered By – Anatoly

Answer Checked By – Clifford M. (AngularFixing Volunteer)

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