I have a mongoose schema like this suppose:-
var mSchema = new Schema({
name: { type: String, required: true}
});
and have been using this schema for a year and now i want to add gender to it like this :-
var mSchema = new Schema({
name: { type: String, required: true},
gender: { type: String, default: 'Male' }
});
whenever there will be an update request i want this gender to automatically set Male as default but i found that default don't set on update request.
(Note: It's just an example not a real life scenario. i just want mongoose default work if field is not present or null)
Is there any way in which i can set default on the updation of document ?
If you are using a function like update(), then this is not directly possible as stated by this answer. Still, you can simply switch to a function like findOne() and use save(), which should do the same.
When upserting documents, you can also check out the setDefaultsOnInsert option: https://mongoosejs.com/docs/defaults.html#the-setdefaultsoninsert-option
const options = {
// Create a document if one isn't found. Required
// for `setDefaultsOnInsert`
upsert: true,
setDefaultsOnInsert: true
};
await XY.findOneAndUpdate(query, update, options);
Related
I'm working on a project that is basically a super watered down social media website.
I have a chunk done already, but I'm having some issues creating a put request to my mongodb. Basically, I want to send a put request to update a numeric value to be able to have a like counter on each post.
What I'm trying do here is send a put request with a specific post id. I'm storing the post id in a hidden text box to reference it. This is pug formatted HTML:
input.form-control(type='hidden' value=item.id id='postId' placeholder='' name='postId' required='false')
form(method='PUT' action='/update/{{post._id}}')
button(type='submit') Like
Then in my router.js file I'm basically trying to take in that id and set the likes field in the Post schema to 1 (just for testing).
router.put('/update/:id', function (req, res, next) {
let id = {
_id: ObjectID(req.params.id)
};
Post.update({_id: id}, {$set:{'likes': 1}}, (err, result) => {
if(err) {
throw err;
}
res.send('user updated sucessfully');
});
});
Here is my post schema
var mongoose = require("mongoose");
var PostSchema = new mongoose.Schema({
postText: {
type: String,
unique: false,
required: true,
trim: true
},
usernameText: {
type: String,
unique: false,
required: true,
trim: true
},
likes:{
type: Number,
unique: false,
required: false
}
});
var Post = mongoose.model("Posts", PostSchema);
module.exports = Post;
Any and all help would be highly appreciated, thank you
You can't change the ObjectId. The ObjectId is generated by MongoDB and can't be changed by the user using query functions.
If you want to assign a unique id to each user for example, then create a separate field in your schema.
You cannot change the ID
'PUT' method is not supported directly as far as I know. You need method override
I am using mongodb with mongoose. And i am wondering if it is possible to have multiple references for an object id attribute in a schema.
I have tried the code underneath and it did not work.
const Schema = new Schema({
refrens: {
type: ObjectId,
// this did not work
ref: [
"Post",
"Account"
],
required: true
}
});
I know it is possible to remove the ref attribute (field, key) and then all object ids are valid but i want certain object ids to be valid, the object ids of the Post and Account model.
const Schema = new Schema({
refrens: {
// This will allow all different types of object ids to be the value
type: ObjectId,
required: true
}
});
Look like refPath is what you need. You can do something like this:
const Schema = new Schema({
refrens: {
type: ObjectId,
refPath: 'onModel',
required: true
},
onModel: {
type: String,
required: true,
enum: ['Post', 'Account']
}
});
I have had a mongoose schema like below:
var schema = mongoose.Schema({
name: String
}
I had some documents with these schema and after a while I've added a new field with a default value :
var schema = mongoose.Schema({
name: String,
job: {type: String, default: function() { return "Job" + this.name.toLowerCase() }}
}
When I get the document (findOne), I can see the default value be set. But when I check the exact row in my database, default value is not set yet!
When I add new documents, the default value is set and everything is alright; but how can I make the old documents' default value be set in database?
Try to updated your old documents using hook :
schema.post('init', function (doc) {
if(!doc.job){
doc.job = "Job" + doc.name.toLowerCase();
doc.save();
}
});
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?
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)
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.
If a user has an array called "tags":
var User = new Schema({
email: {
type: String,
unique: true,
required: true
},
tags: [{
type: mongoose.Schema.Types.ObjectId,
ref:'Tag',
required: true
}],
created: {
type: Date,
default: Date.now
}
});
and I do a populate('tags') on a query:
User.findById(req.params.id)
.populate("tags")
.exec(function(err, user) { ... });
If one of the tags in the list has actually been deleted, is there a way to remove this dead reference in "tags"?
Currently, the returned user object IS returning the desired result -- ie. only tags that actually exist are in the tags array... however, if I look at the underlying document in mongodb, it still contains the dead tag id in the array.
Ideally, I would like to clean these references up lazily. Does anyone know of a good strategy to do this?
I've tried to find some built-in way to do that but seems that mongoose doesn't provide such functionality.
So I did something like this
User.findById(userId)
.populate('tags')
.exec((err, user) => {
user.tags = user.tags.filter(tag => tag != null);
res.send(user); // Return result as soon as you can
user.save(); // Save user without dead refs to database
})
This way every time you fetch user you also delete dead refs from the document. Also, you can create isUpdated boolean variable to not call user.save if there was no deleted refs.
const lengthBeforeFilter = user.tags.length;
let isUpdated = user.tags.length;
user.tags = user.tags.filter(tag => tag != null);
isUpdated = lengthBeforeFilter > user.tags.length;
res.send(user);
if (isUpdated) {
user.save();
}
Assuming you delete these tags via mongoose, you can use the post middleware.
This will be executed after you've deleted a tag.
tagSchema.post('remove', function(doc) {
//find all users with referenced tag
//remove doc._id from array
});
its sample retainNullValues: true
Example:
User.findById(req.params.id)
.populate({
path: "tag",
options: {
retainNullValues: true
}
})