Update all Rows and then send response sequelize

I'm Pretty new doing this kind of tasks in Node. I have a POST method (express) wich recive an array of objects like:

[{F1:'123',F2:'a',F3:'b',F4:'Z'},
{F1:'124',F2:'a',F3:'b',F4:'Z'},
{F1:'125',F2:'a',F3:'b',F4:'Z'},
{F1:'126',F2:'a',F3:'b',F4:'Z'},]

Then, i need do an Update for every object in the array. Im using sequelize :

MODEL.update(
    {
        att4: art['F4'],
    },
    {
    where:{
            att1: {$eq: art['F1']}
          }
    }).then(function(result)
    {        
        res.status(200).send();

    }).catch(function(err)
    {
        res.status(500).send(err);
    }) 

And this work for 1 object.

But i need the following: WHEN ALL THE UPDATES are processed, then send a response.

I try with

req.body.forEach(function(o)
    {
        updateO(o)
    },this);

and in updateO(o) do the Model.Update , but i don't achieve the needed result.

Sorry for the bad english, hope can understand me and thank's for your help.

via federhico