node.js - Mongoose 从数组中删除子文档

Question

    const user = await User.findById(req.user._id);


    // finds index of object in the array to be removed
    var indexToRemove = -1;
    for (var i = 0; i < user.weights.length; i++) {
        if (user.weights[i].date === weightInstance.date) {
            indexToRemove = i;
        }
    }

    if (indexToRemove > -1) {
        // what goes here?
    }

    user.weights.push(weightInstance);
    await user.save();

我想要做的是删除嵌套在用户 (user.weights) 内的 Weight 子文档对象(如果存在)，该对象在日期属性中与我添加到 user.weights 数组中的新 Weight 子文档对象相匹配.

用户架构:

const userSchema = new Schema({
    googleId: String,
    weights: [Weight]
});

权重架构:

const weightSchema = new Schema({
    date: String,
    weight: Number
});

Answer 1

您可以使用 Array.filter 来完成此操作功能:

  // Get the user from database
  const user = await User.findById(req.user._id);

  // Use the function filter to remove every user
  // matching the date in weightInstance
  user.weights = user.weights.filter(x => x.date !== weightInstance.date);

  // Save the modified user
  await user.save();