I have a schema
const mySchema = new Schema({
delta: { type: Number, required: function() { return this.operation === 'change' } },
operation: { type: String, enum: ['change', 'scan'], required: true }
}];
I want delta field to be in the document only when operation has value of 'change'.
When operation has value of 'scan' the document must not have delta.
Is there a way to achieve via schema definition, without using hooks?
Related
I'm creating a medicine reminder web app, that will require the user to enter the data related to medicine and the time at which the reminder will be shown.
So is there any way to store the user input time in the mongodb, there is a type to store date, but couldn't find anything to store time.
This is the mongoose schema
const mongoose = require('mongoose')
const Schema = mongoose.Schema
const medicineSchema = new Schema({
title: {
type: String,
required: true
},
count: {
type: Number,
required: true
},
about: {
type: String
},
time: {
type: TimeRanges,
required: true
}
}, { timestamps: true })
module.exports = mongoose.model('Medicine', medicineSchema)
I tried timeranges but it shows timeranges is not defined, and I don't think timeranges will store time input.
Taking user input through the form
I am using String SchemaType with Date() object.
// Set current date TimeStamp, eg: '1666512804163'
TimeStamp: new Date().getTime().toString()
// Display saved TimeStamp, eg: '23/10/2022'
new Date(parseInt(TimeStamp)).toLocaleDateString()
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);
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'm currently planning out the database structure for an app I'm building, and something in this linked answer raised some questions for me.
In the structure that Shivam proposed, he sometimes references another collection directly, in other words within one Schema he defines the type of a field to be an array of another schema type. Example:
import { Schema } from "mongoose";
import { QuestionSchema } from "./question-schema";
const mongoose = require('mongoose');
export const QuestionSetSchema: Schema = new Schema({
questionSet: {
type: [QuestionSchema],
validate: {
validator: function(value: any) {
return value.length === 12;
},
message: 'Question set must be 12.'
}
},
}, {
timestamps: true
});
In other cases, he only uses an ObjectID reference to another schema/collection:
export const CandidateSchema: Schema = new Schema({
name: String,
email: String, // you can store other candidate related information here.
totalAttempt: {
type: Number,
default: 0,
validate: {
validator: function(value: number) {
return value === 3;
},
message: 'You have already done three attempts.'
}
},
candidateQuestionAnswers: {
type: [Schema.Types.ObjectId],
ref: 'CandidateQuesAnswer'
}
}, {
timestamps: true
});
What are the use cases for each of the above? Does the "type:[otherSchema]" method actually embed instances of that collection or does it only provide their properties to the Schema they are called from?
I have a backend API for an Express/Mongo health tracking app.
Each user has an array of weighIns, subdocuments that contain a value, a unit, and the date recorded. If no unit is specified the unit defaults to 'lb'.
const WeighInSchema = new Schema({
weight: {
type: Number,
required: 'A value is required',
},
unit: {
type: String,
default: 'lb',
},
date: {
type: Date,
default: Date.now,
},
});
Each user also has a defaultUnit field, that can specify a default unit for that user. If that user posts a weighIn without specifying a unit, that weighIn should use the user's defaultUnit if present or else default to 'lb'.
const UserSchema = new Schema({
email: {
type: String,
unique: true,
lowercase: true,
required: 'Email address is required',
validate: [validateEmail, 'Please enter a valid email'],
},
password: {
type: String,
},
weighIns: [WeighInSchema],
defaultUnit: String,
});
Where is correct location for this logic?
I can easily do this in the create method of my WeighInsController, but this seems at best not best practice and at worst an anti-pattern.
// WeighInsController.js
export const create = function create(req, res, next) {
const { user, body: { weight } } = req;
const unit = req.body.unit || user.defaultUnit;
const count = user.weighIns.push({
weight,
unit,
});
user.save((err) => {
if (err) { return next(err); }
res.json({ weighIn: user.weighIns[count - 1] });
});
};
It doesn't seem possible to specify a reference to a parent document in a Mongoose schema, but I would think that a better bet would be in my pre('validate') middleware for the subdocument. I just can't see a way to reference the parent document in the subdocument middleware either.
NB: This answer does not work as I don't want to override all of the user's WeighIns' units, just when unspecified in the POST request.
Am I stuck doing this in my controller? I started with Rails so I have had 'fat models, skinny controllers' etched on my brain.
You can access the parent (User) from a sub-document (WeighIn) using the this.parent() function.
However, I'm not sure if it's possible to add a static to a sub-document, so that something like this would be possible:
user.weighIns.myCustomMethod(req.body)
Instead, you could create a method on the UserSchema, like addWeightIn:
UserSchema.methods.addWeightIn = function ({ weight, unit }) {
this.weightIns.push({
weight,
unit: unit || this.defaultUnit
})
}
Then just call the user.addWeightIn function within your controller and pass the req.body to it.
This way, you get 'fat models, skinny controllers'.