hasOne hasMany problem

[Maxime]

Hi,

I have a problem with two method hasOne and hasMany. 

I have two tables : Driver and Ad

Driver has hasOne(Ad) association

My code :

      let driver = await models.Driver.findById(3, {

        include: [{

          model: models.Ad

        }]

      });

driver.createAd({ 

  message: "HELLO"

});

Why i can create many Ad but association is hasOne ?

The FK driver_id is not unique !

An idea ?

Sorry for my english