how to insert data into many to many association sails js? - sails.js

Question

I am new to sails js, and I want to insert data into mongodb using many to many association , but I don't know which collection should I insert first and how to insert it. Below is my model:
// User.js
module.exports={
attributes:{
firstname:{
type:'string'
},
lastname:{
type:'string'
},
pets:{
collection:'pet',
via:'owners',
dominant: true
}
}
};
// Pet.js
module.exports={
attributes:{
name:{
type:'string'
},
type:{
type:'string'
},
owners:{
collection:'user',
via:'pets'
}
}
};
I tried to insert data into pet collection first , but I didn't see the collection is updated. This is how I insert data into pet collection:
Pet.create({'name':req.body.name,'type':req.body.type}).exec(function(err,data){
if(err) return next(err);
res.json(data);
});
Thank in advance for the help

Answer 1

If you have existing User records, you can specify an array of them when adding your pet:
Pet.create({
'name':req.body.name,
'type':req.body.type,
'owners': [userId1, userId2]
}).exec(function(err,data){
if(err) { return next(err); ]
res.json(data);
});
Or, you can specify the new Pet's ID when adding a new User:
Pet.create({
'name':req.body.name,
'type':req.body.type
}).exec(function(err,newPet){
if(err) { return next(err); ]
User.create({ name: 'tom', pets: [newPet.id] }).exec(function(err, newUser) {
if (err) { return next(err); }
return res.json({ pet: newPet, user: newUser });
});
});
After that, in Sails 0.12.x, you can add/remove items from the collection using the methods documented in the associations docs. In Sails 1.0, you'd use the addToCollection, removeFromCollection and replaceCollection methods.