How to do nested find in mongoose? - node.js

Question

I have a user model which has todolists field, in the todolists field I want to get the specific todolist by id. my query is like this:
User.find({_id: user._id, _creator: user, todoList: todoList._id}, 'todoLists') // how do I query for todoList id here? I used _creator this on populate query.
Can I also do a search on a Usermodel field like this?
User.todoLists.find({todoList: todoList._id})
I haven't tested this yet because I am still modifying my Graphql schema and I am new in mongoose.I would really appreciate Links and suggestions. Help?

Answer 1

Assuming your models looks like this:
const todoListSchema = new Schema({
item: { type: String },
}, { collection: 'todolist' });
const userSchema = new Schema({
todoList: [todoListSchema],
}, { collection: 'user' });
mongoose.model('user', userSchema);
mongoose.model('todoList', todoListSchema);
Now you have multiple ways to do that:
1. Using the array filter() method
reference
User.findById(_id, (err, user) => {
const todoList = user.todoList.filter(id => id.equals(tdlId));
//your code..
})
2. Using mongoose id() method
reference
User.findById(_id, (err, user) => {
const todoList = user.todoList.id(tdlId);
//your code..
})
3. Using mongoose aggregate
reference
User.aggregate(
{ $match: { _id: userId} },
{ $unwind: '$todoList' },
{ $match: { todoList: tdlId } },
{ $project: { todoList: 1 } }
).then((user, err) => {
//your code..
}
});