What type of GUID on Mongoose - node.js

Currently, I used MongoVUE to import from current SQL Server database but all PK with uniqueidentifier were converted to something like "Binary - 3:UuidLegacy
My question is how do is create schema for this structure on Mongoose? I can't see Guid/UUID datatype on Mongoose docs http://mongoosejs.com/docs/api.html#schema_Schema.Types
And for more, I get issue when query with ValidationID something like
db.Validations.find({ValidationID: '1389AB5E-56BD-46FD-9A8A-258C7BDE4251'});
It returns nothing although this Guid is exactly same with SQL Server record.
Thanks.

MongoVUE is obscuring things a bit here, but in a nice way that makes it easier to read. Here's what your example ValidationID of '1389AB5E-56BD-46FD-9A8A-258C7BDE4251' actually looks like - it's type 3 BinData:
{"ValidationID" : BinData(3,"E4mrXla9Rv2aiiWMe95CUQ==")}
The viewer is converting that to a more readable format for you. It's doing that by converting to hex and adding dashes. For proof:
> var bar = BinData(3,"E4mrXla9Rv2aiiWMe95CUQ==")
> bar.hex()
1389ab5e56bd46fd9a8a258c7bde4251
If you want to find that ID, then strip the dashes and pass that into the find as follows (I inserted a sample doc):
> db.foo.find({ValidationID: UUID('1389AB5E56BD46FD9A8A258C7BDE4251')})
{ "_id" : ObjectId("544fd7ddbb4f50c77c61f367"), "ValidationID" : BinData(3,"E4mrXla9Rv2aiiWMe95CUQ==") }
I don't have mongoose set up to test, but have done the leg work in another answer similar to this in terms of converting in javascript.

This drove me crazy for several hours, as a solution I ended up having to install
npm install mongodb --save
npm install slugid --save
and code it as follows
var mongo = require('mongodb');
var slugid = require('slugid');
...
var guidb64 = slugid.encode(guid); // guid is something like '8440d561-1127-4fd8-aca9-54de19465d0b'
guidb64 = guidb64.replace(/_/g, '/'); // for whatever reason slug uses '_' instead of '/' I have in db
guidb64 += '=='; // adding missing trailing '==' I have in db
var GUID = new mongo.Binary(new Buffer(guidb64, 'base64'), 3);
var query = MySchemaType.findOne({ Guid: GUID });
query.exec(function(err, entity) {
// process
})

Related

How to get the id from the given lines of code?

{
acknowledged: true,
insertedId: new ObjectId("612d9d08db9c20f031033478")
}
This was the JSON format I got while I added a file and some other things to MongoDB and I want to get this id separately to save the file to another folder.
Can anyone please explain this?
I believe this question was answered by Vikas in this thread How to get value from specific key in NodeJS JSON [duplicate]
Edited The Answer. Now Its working for above object in question
You can use following function to access the keys of JSON. I have
returned 'mm' key specifically.
function jsonParser(stringValue) {
var string = JSON.stringify(stringValue);
var objectValue = JSON.parse(string);
return objectValue['mm'];
}
if this is a JSON String, at first of all you have to parse it to object liertal, then you can access the specified property you mentioned, so you can do like the following:
function parseJsonString(jsonString) {
// first parse it to object
var obj = JSON.parse(jsonString);
// now access your object property/key
var id = obj.insertedId;
}
If your doing it on mongodb shell or Robo3T then, the line of code would be:
db.collection_name.find({},{insertedId:1})
This is related to projection. 1 represents you want to display it as your output.
In your case as you want only the value of your object id to get displayed, you have to use .valueOf() ; that is ObjectId().valueOf().
-> insertedId: new ObjectId("612d9d08db9c20f031033478")
-> ObjectId("612d9d08db9c20f031033478").valueOf()
->
-> 612d9d08db9c20f031033478
Your can refer this : https://docs.mongodb.com/manual/reference/method/ObjectId.valueOf/ site for your reference.
So you can use this .valueOf() in your code and get the id saved in the document

MongoDB update object and remove properties?

I have been searching for hours, but I cannot find anything about this.
Situation:
Backend, existing of NodeJS + Express + Mongoose (+ MongoDB ofcourse).
Frontend retrieves object from the Backend.
Frontend makes some changes (adds/updates/removes some attributes).
Now I use mongoose: PersonModel.findByIdAndUpdate(id, updatedPersonObject);
Result: added properties are added. Updated properties are updated. Removed properties... are still there!
Now I've been searching for an elegant way to solve this, but the best I could come up with is something like:
var properties = Object.keys(PersonModel.schema.paths);
for (var i = 0, len = properties.length; i < len; i++) {
// explicitly remove values that are not in the update
var property = properties[i];
if (typeof(updatedPersonObject[property]) === 'undefined') {
// Mongoose does not like it if I remove the _id property
if (property !== '_id') {
oldPersonDocument[property] = undefined;
}
}
}
oldPersonDocument.save(function() {
PersonModel.findByIdAndUpdate(id, updatedPersonObject);
});
(I did not even include trivial code to fetch the old document).
I have to write this for every Object I want to update. I find it hard to believe that this is the best way to handle this. Any suggestions anyone?
Edit:
Another workaround I found: to unset a value in MongoDB you have to set it to undefined.
If I set this value in the frontend, it is lost in the REST-call. So I set it to null in the frontend, and then in the backend I convert all null-values to undefined.
Still ugly though. There must be a better way.
You could use replaceOne() if you want to know how many documents matched your filter condition and how many were changed (I believe it only changes one document, so this may not be useful to know). Docs: https://mongoosejs.com/docs/api/model.html#model_Model.replaceOne
Or you could use findOneAndReplace if you want to see the document. I don't know if it is the old doc or the new doc that is passed to the callback; the docs say Finds a matching document, replaces it with the provided doc, and passes the returned doc to the callback., but you could test that on your own. Docs: https://mongoosejs.com/docs/api.html#model_Model.findOneAndReplace
So, instead of:
PersonModel.findByIdAndUpdate(id, updatedPersonObject);, you could do:
PersonModel.replaceOne({ _id: id }, updatedPersonObject);
As long as you have all the properties you want on the object you will use to replace the old doc, you should be good to go.
Also really struggling with this but I don't think your solution is too bad. Our setup is frontend -> update function backend -> sanitize users input -> save in db. For the sanitization part, we use a helper function where we integrate your approach.
private static patchModel(dbDocToUpdate: IModel, dataFromUser: Record<string, any>): IModel {
const sanitized = {};
const properties = Object.keys(PersonModel.schema.paths);
for (const key of properties) {
if (key in dbDocToUpdate) {
sanitized[key] = data[key];
}
}
Object.assign(dbDocToUpdate, sanitized);
return dbDocToUpdate;
}
That works smoothly and sets the values to undefined. Hence, they get removed from the document in the db.
The only problem that remains for us is that we wanted to allow partial updates. With that solution that's not possible and you always have to send everything to the backend.
EDIT
Another workaround we found is setting the property to an empty string in the frontend. Mongo then also removes the property in the database

Inserting a variable as a key in MongoDB

I am retrieving JSON data from an API and this is a short example of it:
{"hatenames":
{"id":6239,
"name":"hatenames",
"stat1":659,
"stat2":30,
"stat3":1414693
}
}
I am trying to insert it in the MongoDB (using MongoClient) but it won't let me put just the object directly or use a variable as a field name. If I put the var username it will just output it as username in the database field. This is what I would like to work:
collection.insert({object}
collection.insert({username:object[username]}
but it doesn't and I've been stuck on this for the past few hours. The only resolution I found was to set it and then update the field name afterwards, but that just seems lame to have to do every single time, is there no elegant or easy option that I am somehow missing?
First of all, being a programmer, you should forget about "it does not work" phrase. You should describe how it does not work with exact error messages you encounter. Not to your problem.
Just because I can easily do
db.coll.insert({"hatenames":
{"id":6239,
"name":"hatenames",
"stat1":659,
"stat2":30,
"stat3":1414693
}
})
or var a = {"hatenames":{"id":6239, "name":"hatenames", "stat1":659, "stat2":30, "stat3":1414693}}; and db.coll.insert(a),
I think that the problem is that your object is not really an object, but a string. So I suspect that you have a string returned to you back from that API. Something like '{"hatenames":{...}' and this caused a problem when you try to save it or access the properties. So try to convert it to JSON.
Try doing this:
MongoClient.connect('mongodb://127.0.0.1:27017/db_name', function(err, db) {
if(err) throw err;
someCollection = db.collection('some_collection');
});
someCollection.insert({
name: hatenames['name']
});
EDIT
For Dynamic approach, I would suggest you to play aroung this function:
Object.keys(hatenames)
this function will return keys in array.
EDIT 2
I have founded a link: Insert json file into mongodb using a variable
See, if that helps.

mongo query - does property exist?

Within a collection document there is a 'sub' property that is an object containing 1 or more properties. The collection looks like: (I've removes extraneous other properties)
"properties": {
"source": {
"a/name": 12837,
"a/different/name": 76129
}
}
I need to do a find on the collection where a/name and a/different/name are variables.
The variables have embedded front slashes because they are mqtt topic names, in case you wonder.
(node.js)
I've tried:
collection.find({'properties.source[variable containing name]': {$exists: true}}).toArray(function...
Doesn't work, nothing returned
I've also tried setting a query string as in:
var q = util.format('properties.source.%s', variable containing name);
collection.find({q: {$exists: true}}).toArray(function...
Fails with query error
I could replace the front slashes with some other character if they are the problem but I suspect they are ok. I have tried escaping the front slashes and it makes no difference.
Any suggestions?
You can't directly use a variable as an object key, so you need to change it to something like:
var name = 'a/name';
var query = {};
query['properties.source.' + name] = {$exists: true};
collection.find(query).toArray(function...
As you have properties an object and source is also an object, You should use $exist in a query like following :
db.collection.find({"properties.source.a/name":{$exists:true}})

Sailsjs: dynamic tableName in model

I am building my first sailsjs and nodejs application, and it great :)
My situation, I have about 100 tables with the same stucture, I would like to decide "on the fly" which table to load.
my first thought was use somehow a dynamic class names. But I dont know how to do this with nodejs, maybe some one have an idea.
So I would create 100 "modelName".js files in my models folder.
I can use this in browser
window["fileName"].find()....
But I don't have any window object in nodejs
Second idea was to pass the tableName to the model, the problem is, I have to reinit the model, don't know how.
Any solutions?
Found a solution
var modelName = req.param('p');
this[modelName].find()...
Own answer by author is correct, but I will add something just for people who will use it in the future - you can get modelName from req.options.model when you are using Blueprints.
Unfortunately you can't use this[modelName] as option is giving you model name starting with small letter, so first you have to upper case first letter with e.g. var modelName = req.options.model.charAt(0).toUpperCase() + req.options.model.slice(1);
and then you are free to use this[modelName].whateverYouNeed
I used it for generic policy to let user editing only his own group elements.
var modelName = req.options.model.charAt(0).toUpperCase() + req.options.model.slice(1)
var elementID = null
if (req.params.id) { // To handle DELETE, PUT
elementID = req.params.id
}
if (req.body.id) { // To handle POST
elementID = req.body.id
}
this[modelName].findOne({
id: elementID
}).exec(function(err, contextElement) {
if(err) {
return res.serverError(err)
}
if(contextElement.group=== req.user.group.id) {
sails.log('accessing own: ' + modelName)
return next()
}
else {
return res.forbidden('Tried to access not owned object')
}
})
An alternative:
sails.models[Model].findOne({...})
Make sure to have your "Model" name as string in lowercase. It works like accessing a property inside an object
Another option that worked for me:
var modelName = "User";
global[modelName].find()....

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