如何使trim() 函数在node.js 代码中工作，即使没有在mongoose 的模型模式中使用？

Question

I've a mongodb collection which stores "Customers" data. I need to trim the mobile number of a customer if there are any trailing or leading white spaces available. I've used trim() function to remove them. But am getting an error, trim() is not a function .

Here's my model schema:

var schema = mongoose.Schema({
    name    : {type: String, required: true},
    email   : {type: String, required: true},
    mobile  : {type: String, required: true, index: false, unique: false});

module.exports = mongoose.model("customer", schema);

Here's the code where I've used trim function:

addNewCustomer: async function(payload){
  var customer = new Customer({
     name  : payload.name,
     email : payload.email,
     mobile: payload.mobile.trim()
  });
}

When I execute the above function, it is giving me the error. But if I use trim() at schema level, it is working fine.

mobile  : {type: String, required: true, index: false, unique: false, trim: true});

What is the difference between using trim() in SCHEMA level and FUNCTIONALITY level? Why it is not working when used in function?

Answer 1

Have seen functional alternative 'cursor' syntax ala:

db.collection.find({},{ "category": 1 }).forEach(function(doc) {
  db.collection.update(
    { "_id": doc._id },
    { "$set": { "category": doc.category.trim() } }
  );
})

Above example copied from: https://stackoverflow.com/a/46554968/2003321