Transform JSON Response Field Name In Mongoose Model - mongodb

Question

My JSON response contains a field first_name but I want my Mongoose model to represent this field as firstName. Is this possible and if so then how?

Answer 1

You can create a new object with different property names from the one Mongoose returns. A nice way of doing this is to create a transform function. For example, let's say this is your schema:
{
firstName: { type: String, required: true },
lastName: { type: String, required: true }
}
Then you can use this function to create a new object with the desired property names:
function transformDocument (doc) {
return {
first_name: doc.firstName,
last_name: doc.lastName
}
}
Then, when you query the DB, you apply this function to the response:
Person.findOne({ firstName: 'John', lastName: 'Smith' })
.then(transformDocument)

Answer 2

Doug W has a good solution, but if you don't want to be using Promises and chaining .thens, then you can simply add options to the schema like this:
const mongoose = require ('mongoose'); // I am using v5.9.1 at the moment
const { Schema } = mongoose.Schema;
// Specify an options object
const options = {
toJSON: {
versionKey: false
}
// If you ever send the query result as an object,
// you may remove it from there, too, if you wish
// toObject: {
// versionKey: false
// }
};
// Attach the options object to the schema by
// passing it into Schema as the second argument
const mySchema = new Schema({
/** define your schema */
}, options);
This will still save __v to the document in the database. But it will not appear on the json/object when it is the result of a mongoose query.
Besides setting versionKey: false in the options, you may also specify a transform function:
/* ... */
// Specify an options object
const options = {
toJSON: {
// versionKey: false,
transform: function(doc, ret) {
// ret is the object that will be returned as the result
// (and then stringified before being sent)
delete ret.__v;
return ret;
}
}
};
/* ... */
I know this question is nearly two years old, but I needed an answer to this question, and google was not kind to me at the time. I figured it out, and now I'm hoping someone else will be looking for an answer here and find that they have options. Pun not originally intended.