更新猫鼬记录内数组内的值

Question

User Schema:

var userSchema = new mongoose.Schema({
    user: String,
    data: [{}]
});

In the schema above, I am adding question and option(MCQ) user marked inside the data array. I can add new answers successfully but can't update already answered question with different options.

Server side code:

let user = await User.findOne({ user: req.body.user });
let checkUser = user.data.filter(res => res.quesId == req.body.id);
if (checkUser.length) {
    // Logic for updating
} else {
    await user.data.push({
        quesId: req.body.id,
        option: req.body.opt
    });
    user.save();
}

So what I want to do is that if the user answered the same question(determined by req.body.id ) with different option( req.body.opt ), it should be updated in the already existing record.

Answer 1

To update an object inside an array, you need to remove the original object then create a new one with the new data included.

Example:

// Define required variables
let user = await User.findOne({ user: req.body.user });
let data = user.data;
let checkUser = data.filter(res => res.quesId == req.body.id);

// If the question already exists
if (checkUser.length > 0) {
    // Loop through the questions that already exist
    checkUser.forEach(question => {
        // Remove the question from the users data
        data.splice(data.indexOf(question), 1);
        // Append the new data onto the array
        data.push({
            quesId: req.body.id,
            option: req.body.opt
        });
        // Save the new data
        user.data = data;
        user.save();
    });
} else {
    // If the question doesn't already exist, create it
    (user.data).push({
        quesId: req.body.id,
        option: req.body.opt
    });
    // Save the changed data
    user.save();
}