I'm using mongoose to do some MongoDB operations.
At the beginning the category was number,
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const sampleSchema = new Schema({
category: {
type: Number,
}
})
module.exports = mongoose.model("SampleSchema", sampleSchema);
Now the category changed to String, So I changed the model like this
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const sampleSchema = new Schema({
category: {
type: String,
}
})
module.exports = mongoose.model("SampleSchema", sampleSchema);
The problem is, I have already inserted 200 records into this collection. Is there any way to update the category value with a string and change its type to string?
Please get All data by query and update it one by one in loop.
Like:
db.tableName.find( { 'status' : { $type : 1 } } ).forEach( function (val) {
val.status = new String(val.status);
db.tableName.save(val);
});
I changed the category to mixed, that's working fine with numbers and string.
Thanks for the help #prasad_
Related
My Schema
const mongoose = require('mongoose');
const test_schema = new mongoose.Schema({
Name: {
type: String
}
});
const chatting = mongoose.model('chat', test_schema);
module.exports = chatting;
Getting model of above give the schema
const chat = require('./models/chatting.js');
Save Variables
const one = new chat({
Name : "John"
})
const two = new chat({
Name : "John"
})
Now Saving
await chat.insertMany([one, two])
but i got duplicate name key error
You provided a wrong schema to us. (test_schema != chatting_schema). check your chatting schema and see if it is structured somewhat like this:
const chatting_schema = new mongoose.Schema({
Name: {
type: String
unique: true
}
});
if so, remove the unique property.
also, when you already created a document you can just use the .save() function like
await one.save();
I need a unit64 ID in my MongoDB database. ObjectIds are 96 bits.
I have seen the answer here that one way to do it is to add a few constant characters to the beginning of the ID. But how d I achieve this in Mongoose?
Suppose that I have a schema like this:
var mongoose = require('mongoose');
var schema = new mongoose.Schema({
_id: {
???
},
});
I ended up using nanoid for now:
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const { customAlphabet } = require('nanoid');
const alphabet = '123456789';
const nanoid = customAlphabet(alphabet, 19); //from 11...111 to 99...999
const mySchema = new Schema({
int_id: {
type: String,
unique: true,
default: () => nanoid()
},
});
book.schema.js
const mongoose = require('mongoose')
const Schema = mongoose.Schema
const BookSchema = new Schema({
name: {
type: String,
required: true
}
})
module.exports = BookSchema
book.model.js
const mongoose = require('mongoose')
const BookSchema = require('../schema/book.schema')
const Book = mongoose.model('Book', BookSchema)
module.exports = Book
novel.schema.js
const mongoose = require('mongoose')
const Schema = mongoose.Schema
const NovelSchema = new Schema({
name: {
type: String,
required: true
},
type: {
type: Schema.Types.ObjectId,
ref: 'Book'
}
})
module.exports = NovelSchema
novel.model.js
const mongoose = require('mongoose')
const NovelSchema = require('../schema/novel.schema')
const Novel = mongoose.model('Novel', NovelSchema)
module.exports = Novel
query
// Mongoose Populate cant get this to work
// I am at a loss
Novel.findById('5b87310d41073743856a7c4a').populate({
path: 'books'
})
mongoose populate not working。
Please let me know what I am doing wrong or give me a simple explanation...Thank you...
You are right to use the populate for loading the subdocument, but you need to pass the name of the book field in the novel schema, in your case the name is type.
Here is the link to documentation with some examples: Mongoose Populate
And below is the more one solution to your problem:
let book = await new BookModel({name:"book test"}).save();
console.log('-----------BOOK ITEM-------------');
console.log(book);
let novel = await new NovelModel({name:"novel test",type:book._id}).save();
console.log('-----------NOVEL ITEM-------------');
console.log(novel);
let itemPopulated = await NovelModel.findById(novel._id)
.populate('type')
.then((result) => {
return result;
}).catch((err) => {
console.log(err);
});
console.log('-----------ITEM POPULATED-------------');
console.log(itemPopulated);
And the execution output:
The parameter on the function populate() is the path of the field you want to populate, and also when you use populate or any chained function in mongoose you have to use the exec() function in the ending, so the correct way to do it would be:
Novel.findById('5b87310d41073743856a7c4a').populate({
path: 'type'
}).exec()
My mongo record is like this:
{
"_id":{"$oid":"5550b6de437f572112a29f1a"},
"cv_count":177732,
"gender_info": {"male_count": 50, "female_count": 32}
"stability_info_list":[{"ratio":8.802558610369414e-05,"total_count":34081,"years":0},{"ratio":5.868372406912943e-05,"total_count":34081,"years":1}],
"zhineng_id":"IT Manager"
}
I write the schema like this:
var ZhinengGenderSchema = new Schema({
male_count: Number,
female_count: Number
});
var ZhinengStabilitySchema = new Schema({
ratio: Number,
total_count: Number,
years: Number
});
var ZhinengStats = new Schema({
cv_count: Number,
gender_info: ZhinengGenderSchema,
stability_info_list: [ZhinengStabilitySchema],
zhineng_id: String
})
But I got this excetion:
TypeError: Undefined type `undefined` at `gender_info`
Did you try nesting Schemas? You can only nest using refs or arrays.
so mongoose doesn't support nest schemas? But my database has already been there, I cannot change, so how can I define my schema?
Just don't create a new schema for the subdocuments and you should be fine, i.e.:
var ZhinengGenderSchema = {
male_count: Number,
female_count: Number
};
var ZhinengStabilitySchema = {
ratio: Number,
total_count: Number
years: Number
};
var ZhinengStats = new Schema({
cv_count: Number,
gender_info: ZhinengGenderSchema,
stability_info_list: [ZhinengStabilitySchema],
zhineng_id: String
})
With mongoose you can define nesting (embedded) schemas in Array, like this:
var mongoose = require('mongoose'),
Schema = mongoose.Schema;
var bookSchema = new Schema({
value: { type: String }
});
var authorSchema = new Schema({
books: [bookSchema]
});
Or by reference
var mongoose = require('mongoose'),
Schema = mongoose.Schema,
ObjectId = mongoose.Schema.Types.ObjectId;
var auhtorSchema = new Schema({
book: { type: ObjectId, ref: 'Book'}
});
You may choose what is more appropriate for you
As far as I know, this is due to a current limitation of Mongoose. You cannot
declare a schema field to include a single sub-document: you have to use an array, instead. See this: https://github.com/Automattic/mongoose/pull/585
You can set up later the proper business logic in order to ensure that only one sub-element will be added.
Try this:
var ZhinengStats = new Schema({
cv_count: Number,
gender_info: [ZhinengGenderSchema],
stability_info_list: [ZhinengStabilitySchema],
zhineng_id: String
})
This way, each sub-document has got its own _id in MongoDB (even though it does not lie in a specific collection). See more: http://mongoosejs.com/docs/subdocs.html
You could also prefer something like this:
var ZhinengStats = new Schema({
cv_count: Number,
gender_info: [{male_count: Number, female_count: Number}],
stability_info_list: [ZhinengStabilitySchema],
zhineng_id: String
})
In this case, you nest a schema inside another. The single gender_info element does not have the dignity of a document.
Using node.js, mongodb on mongoHQ and mongoose. I'm setting a schema for Categories. I would like to use the document ObjectId as my categoryId.
var mongoose = require('mongoose');
var Schema = mongoose.Schema,
ObjectId = Schema.ObjectId;
var Schema_Category = new Schema({
categoryId : ObjectId,
title : String,
sortIndex : String
});
I then run
var Category = mongoose.model('Schema_Category');
var category = new Category();
category.title = "Bicycles";
category.sortIndex = "3";
category.save(function(err) {
if (err) { throw err; }
console.log('saved');
mongoose.disconnect();
});
Notice that I don't provide a value for categoryId. I assumed mongoose will use the schema to generate it but the document has the usual "_id" and not "categoryId". What am I doing wrong?
Unlike traditional RBDMs, mongoDB doesn't allow you to define any random field as the primary key, the _id field MUST exist for all standard documents.
For this reason, it doesn't make sense to create a separate uuid field.
In mongoose, the ObjectId type is used not to create a new uuid, rather it is mostly used to reference other documents.
Here is an example:
var mongoose = require('mongoose');
var Schema = mongoose.Schema,
ObjectId = Schema.ObjectId;
var Schema_Product = new Schema({
categoryId : ObjectId, // a product references a category _id with type ObjectId
title : String,
price : Number
});
As you can see, it wouldn't make much sense to populate categoryId with a ObjectId.
However, if you do want a nicely named uuid field, mongoose provides virtual properties that allow you to proxy (reference) a field.
Check it out:
var mongoose = require('mongoose');
var Schema = mongoose.Schema,
ObjectId = Schema.ObjectId;
var Schema_Category = new Schema({
title : String,
sortIndex : String
});
Schema_Category.virtual('categoryId').get(function() {
return this._id;
});
So now, whenever you call category.categoryId, mongoose just returns the _id instead.
You can also create a "set" method so that you can set virtual properties, check out this link
for more info
I was looking for a different answer for the question title, so maybe other people will be too.
To set type as an ObjectId (so you may reference author as the author of book, for example), you may do like:
const Book = mongoose.model('Book', {
author: {
type: mongoose.Schema.Types.ObjectId, // here you set the author ID
// from the Author colection,
// so you can reference it
required: true
},
title: {
type: String,
required: true
}
});
My solution on using ObjectId
// usermodel.js
const mongoose = require('mongoose')
const Schema = mongoose.Schema
const ObjectId = Schema.Types.ObjectId
let UserSchema = new Schema({
username: {
type: String
},
events: [{
type: ObjectId,
ref: 'Event' // Reference to some EventSchema
}]
})
UserSchema.set('autoIndex', true)
module.exports = mongoose.model('User', UserSchema)
Using mongoose's populate method
// controller.js
const mongoose = require('mongoose')
const User = require('./usermodel.js')
let query = User.findOne({ name: "Person" })
query.exec((err, user) => {
if (err) {
console.log(err)
}
user.events = events
// user.events is now an array of events
})
The solution provided by #dex worked for me. But I want to add something else that also worked for me: Use
let UserSchema = new Schema({
username: {
type: String
},
events: [{
type: ObjectId,
ref: 'Event' // Reference to some EventSchema
}]
})
if what you want to create is an Array reference. But if what you want is an Object reference, which is what I think you might be looking for anyway, remove the brackets from the value prop, like this:
let UserSchema = new Schema({
username: {
type: String
},
events: {
type: ObjectId,
ref: 'Event' // Reference to some EventSchema
}
})
Look at the 2 snippets well. In the second case, the value prop of key events does not have brackets over the object def.
You can directly define the ObjectId
var Schema = new mongoose.Schema({
categoryId : mongoose.Schema.Types.ObjectId,
title : String,
sortIndex : String
})
Note: You need to import the mongoose module
Another possible way is to transform your _id to something you like.
Here's an example with a Page-Document that I implemented for a project:
interface PageAttrs {
label: string
// ...
}
const pageSchema = new mongoose.Schema<PageDoc>(
{
label: {
type: String,
required: true
}
// ...
},
{
toJSON: {
transform(doc, ret) {
// modify ret directly
ret.id = ret._id
delete ret._id
}
}
}
)
pageSchema.statics.build = (attrs: PageAttrs) => {
return new Page({
label: attrs.label,
// ...
})
}
const Page = mongoose.model<PageDoc, PageModel>('Page', pageSchema)
Now you can directly access the property 'id', e.g. in a unit test like so:
it('implements optimistic concurrency', async () => {
const page = Page.build({
label: 'Root Page'
// ...
})
await page.save()
const firstInstance = await Page.findById(page.id)
const secondInstance = await Page.findById(page.id)
firstInstance!.set({ label: 'Main Page' })
secondInstance!.set({ label: 'Home Page' })
await firstInstance!.save()
try {
await secondInstance!.save()
} catch (err) {
console.error('Error:', err)
return
}
throw new Error('Should not reach this point')
})