Sequelize: seed with associations

Question

I have 2 models, Courses and Videos, for example. And Courses has many Videos.

// course.js
\'use strict\';

module.exports = (sequelize, DataTypes) => {
  co         


        

Answer 1

The bulkInsert method returns a promise that is resolved with an ID of the first inserted item. We can use this information to insert videos. It can look like this:

function getId( firstId, items, needly ) {
    for ( let i = 0; i < items.length; i++ ) {
        if ( items[i].title === needly ) {
            return firstId + i;
        }
    }

    return null;
}

exports.up = async ( queryInterface, Sequelize ) => {
    const courses = [
        {
            title: 'Course 1',
            description: '...',
        },
        {
            title: 'Course 2',
            description: '...',
        },
        {
            title: 'Course 3',
            description: '...',
        },
        {
            title: 'Course 4',
            description: '...',
        },
        {
            title: 'Course 5',
            description: '...',
        },
    ];

    const firstId = await queryInterface.bulkInsert( 'courses', courses, {} );
    const course2Id = getId( firstId, courses, 'Course 2' );
    const course5Id = getId( firstId, courses, 'Course 5' );

    return queryInterface.bulkInsert( 'categories', [
        { title: 'Video 1', description: '...', courseId: course2Id },
        { title: 'Video 2', description: '...', courseId: course2Id },
        { title: 'Video 3', description: '...', courseId: course5Id },
        { title: 'Video 4', description: '...', courseId: course5Id },
        { title: 'Video 5', description: '...', courseId: course5Id },
    ], {} );
};

exports.down = async ( queryInterface ) => {
    await queryInterface.bulkDelete( 'videos', null, {} );
    await queryInterface.bulkDelete( 'courses', null, {} );
}