Sequelize Many to Many

test.js

// sqlconnection is sequelize, connected properly.

class Post extends Model {
}

Post.init({
    name: DataTypes.STRING,
    description: DataTypes.STRING
}, {
    sequelize: sqlconnection,
    modelName: 'Post'
})

class Tag extends Model {
}

Tag.init({
    name: DataTypes.STRING,
    description: DataTypes.STRING
}, {
    sequelize: sqlconnection,
    modelName: 'Tag'
})

// relationships

Tag.belongsToMany(Post, {
    through: {
        model: 'PostTags'
    }
})

Post.belongsToMany(Tag, {
    through: {
        model: 'PostTags'
    }
})

// actually saving to db

Tag.create({
        name: "Photography",
        description: "tag for photo related things."
    })

Post.create({
    name: "a photo",
    description: "a description",
    Tags: [{name: 'Photography'}]
}, {
    include: [ Tag ]
})