Get the data from related tables (models) sequelize

» mysql » Get the data from related tables (models) sequelize

By : Trishan

Date : December 01 2020, 05:00 PM

Does that help Let's say I have these tables: , You have to first define the association in your models

code :

'use strict';
module.exports = function ( sequelize, DataTypes ) {

var users = sequelize.define( 'users', {
    name: DataTypes.STRING( 50 ),
    countryId: DataTypes.INTEGER,
}, {
    classMethods: {
        associate: function ( models ) {
            users.belongsTo(models.countries, {foreignKey: countryId})
        }
    }
} );

return users;

};

models.users.findAll( {

    order: [ [ request.query.orderBy, request.query.sort ] ],
    include: [{
        model: models.countries
    }]
} ).then( function ( users ) {

    // do some formating on the output

} );

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Trying to return data from related models from one endpoint in Tastypie, but the related data are always empty

By : martin J

Date : March 29 2020, 07:55 AM

Hope this helps I'm a new user of the Tastypie package for Django and have got my API up and running. I have one endpoint which is trying to return one model and its related model's data. Even though I'm not getting any errors, the related model's data is always empty (see following example): , This line is critical:

code :

collection = fields.ToManyField('maps.api.resources.CollectionResource', \
                 attribute='collections', full=True, null=True)

from django.contrib.auth.models import User
def Collection(models.Model):
    ...
    user = models.ForeignKey(User, related_name='collections')

Change the names property on query of two related models SEQUELIZE

By : Riley Grogan

Date : March 29 2020, 07:55 AM

This might help you That is because of raw: true, just remove that line and you are all good to go ,
I think you have used raw:true to get plain object from query and not extra params with that , you can that in this by using toJSON() property ,

code :

User.findOne({
  include: [
    { model: Image,attributes: ["name"],required: true},
  ]
}).then((user){
  user = user.toJSON(); // here , this way
}

How do you insert / find rows related by foreign keys from different tables using Sequelize?

By : user782087

Date : March 29 2020, 07:55 AM

wish helps you
Is it possible insert and retrieve several rows related at the same time and getting / using a single Sequelize command / object? How?

code :

const User = sequelize.define('user', {
  username: Sequelize.STRING,
});

const Address = sequelize.define('add', {
  address: Sequelize.STRING,
});

const Designation = sequelize.define('designation', {
  designation: Sequelize.STRING,
});

User.hasOne(Address);
User.hasMany(Designation);

sequelize.sync({ force: true })
  .then(() => User.create({
    username: 'test123',
    add: {
      address: 'this is dummy address'
    },
    designations: [
      { designation: 'designation1' },
      { designation: 'designation2' },
    ],
  }, { include: [Address, Designation] }))
  .then(user => {
    User.findAll({
      include: [Address, Designation],
    }).then((result) => {
      console.log(result);
    });
  });

Why are all the Sequelize example models instantiated with Model(sequelize, Sequelize)?

By : user1524359

Date : March 29 2020, 07:55 AM

like below fixes the issue That is really ugly. What I do is I create a db in it's own file and export it.

code :

const db = new Sequelize(
  process.env.DATABASE_URL || `postgres://localhost:5432/${databaseName}`,
)

module.exports = db

const Sequelize = require('sequelize')
const db = require('../db')

const blog = db.define('blog', {
  your_field_name_here: {
    type: your_sequelize_type_here
  },
  ... and so on
})

module.exports = blog

Optimizing queries on related tables in Sequelize

By : user3716619

Date : March 29 2020, 07:55 AM

Does that help Oh i totally missed that.. it was late.. yes you can do that.. add the as like below to alias this connection, and do the same in songs with as: 'instruments'... you don't need to fetch the join records..

code :

Instrument.associate = function (models) {
        Instrument.belongsToMany(models.songs, {through: 'songs_instruments', as: 'songs', foreignKey: 'instrument_id', otherKey: 'song_id'})
    };

const instruments = await db.instruments.findAll({
    where: {name: args['instruments']},
    {
     include: [{
        model: db.songs,
        as: 'songs', 
        through: db.songs_instruments,
      }]
   }
});

const songs = await db.songs.findAll({
          include: [{
            model: db.instruments,
            as: 'instruments', 
            through: db.songs_instruments,
            where: {name: args['instruments']}
          }],
        });