I'm trying to use TypeORM with MongoDB and express but I'm having problems with the basic stuff.
I just created a controller with basic CRUD operations for an entity. The methods save, findAll and find by Filter works ok, but I can't make the methods that require an mongo id work.
router.get("/", async(req: Request, res: Response) => {
const investmentRepository = getMongoRepository(Investment);
const investments = await investmentRepository.find();
res.send(investments);
});
router.get("/:id", async(req: Request, res: Response) => {
const investmentRepository = getMongoRepository(Investment);
const investment = await
investmentRepository.findOneById(req.params.id);
if (!investment) {
res.status(404);
res.end();
}
res.send(investment);
});
The second method is always returning 404.
For example, this is an entity returned on get all "investment/"
{
"id": "59dfd8cadcbd9d1720457008",
"name": "Teste LCI",
"startDate": 1466305200,
"numberOfDays": 365,
"type": "LCI_LCA"
}
If I try to send a request for this specific object calling
investment/59dfd8cadcbd9d1720457008
the response is always 404.
The same behavior happen with the delete method, raising an exception
Cannot find entity to remove by a given id
I also tried to convert the string to ObjectID using:
new ObjectID(req.params.id);
but it fails with the error ObjectID is not a constructor.
If you're receiving the error ObjectId is not a constructor it is because you forgot to require it in your file. All you need is:
const ObjectId = require('mongodb').ObjectId;
Related
I'm writing a function in MongoDB Realm that I want to use as a custom resolver for GraphQL. Part of the function should get a specific document by its id. According to the documentation I can get access to the Atlas DB by using context.services.get('mongodb-atlas'). Here's the simplified code extract:
exports = async () => {
const cluster = context.services.get('mongodb-atlas');
const collection = cluster.db('my-db').collection('my-coll');
return await collection.findOne({"_id": "61d33d2059c38ef0584c94f8"});
}
However, the findOne() call returns null. I know that the id above is valid, because I can successfully call collection.find() and list all the documents with their ids.
What I've tried
findOne({"_id": "61d..."}) - returns null
findOne({"_id": new ObjectId("61d...")}) - error: "ObjectId" is not defined.
Explicitly declaring ObjectId with const ObjectId = require('mongodb').ObjectId as recommended here - error: "MongoDB Node.js Driver is not supported".
Declaring ObjectId with const ObjectId = require('bson').ObjectId - findOne() returns null again.
Can you recommend any other avenue by which to do this lookup?
First thing I would suggest is - let's identify where the script is failing.
We know for certain, the below should work.
exports = async () => {
let tmp_collection = context.services.get("mongodb-atlas").db("my-db").collection("my-coll");
return await tmp_collection.findOne({});
}
After you can confirm that the above works, give this a try:
return await context.services.get("mongodb-atlas").db("my-db").collection("my-coll").findOne({"_id":new BSON.ObjectId("61d33d2059c38ef0584c94f8")});
Here is your code, but fixed:
exports = async () => {
const cluster = context.services.get('mongodb-atlas');
const collection = cluster.db('my-db').collection('my-coll');
return await collection.findOne({"_id": new BSON.ObjectId("61d33d2059c38ef0584c94f8")});
}
I have a database of activities in MongoDB, had all the basic CRUD operations working fine but now at the point in developing the front end of the app where I need to do a GET request for a single activity in the database. I have working PUT and DELETE requests for single activities but for some reason the GET one just isn't playing ball - it's returning an array of objects rather than a single object with that ID.
I'm currently using Postman to make the requests while I iron this problem out. Mongoose version is 5.12.13.
router.get('/:id', async (req, res) => {
try {
const activity = await Activities.findById(req.params.id)
res.json(activity).send()
} catch (error) {
res.send(error.message)
}
})
Then making a request using Postman to http://localhost:5000/api/activities?id=60968e3369052d084cb6abbf (the id here is just one I've copied & pasted from an entry in the database for the purposes of troubleshooting)
I'm really stumped by this because I can't understand why it's not working! The response I get in Postman is an array of objects, like I said, which seems to be the entire contents of the database rather than just one with the queried ID...
Try calling exec on your findById, findById returns a query, you need to call exec to execute your query.
Without the call to the exec function, your 'activity' variable is a mongoose query object.
router.get('/:id', async (req, res) => {
try {
const activity = await Activities.findById(req.params.id).exec();
res.json(activity).send()
} catch (error) {
res.send(error.message)
}
});
Docs for findById
https://mongoosejs.com/docs/api.html#model_Model.findById
Edit:
As righty spotted by Dang, given your code is inspecting req.params the URL you're calling needs updating to:
http://localhost:5000/api/activities/60968e3369052d084cb6abbf
I,m learning MongoDB and mongoose and now I have a problem in defining a 404 status for my route handler. Here is the code:
app.get('/users/:id', async (req, res) => {
const _id = req.params.id
try {
const user = await User.findById(_id)
if (!user) {
return res.status(404).send()
}
res.send(user)
} catch (error) {
res.status(500).send()
}
})
Now if I give it an id that doesn't exist, it doesn't give me 404 Not Found status. it only executes the catch block which is not what I want.
I would appreciate it if you tell me where I made mistake or tell me a way to get error handling for that.
Thanks
The problem
As you can see in the log
CastError: Cast to ObjectId failed for value "6082d50a2c89db3164" at path "_id" for model "User"
It means : the value you provide to findById function ("6082d50a2c89db3164") is not a valid ObjectId.Then the catch block is executed.
Suggestion
1. Validate the parameter before query in database
I understand that you're trying to provide some id that doesn't exist in the database to test. But IMHO, there a difference between 2 cases :
you provide a valid id, and this id cannot be found in the database. It should return 404 in this case
you provide an invalid id in the request, it could be a string like "6082d50a2c89db3164", or even "#Q*&$(##*" or anything we could imagine. For this case, it could be better if we validate the input (req.params._id) to ensure that the format is valid. The code will be something like this:
app.get('/users/:id', async (req, res) => {
const _id = req.params.id;
// validate params
if(!isValidateObjectId(_id)) { // the function we need to write
res.status(200).send("Invalid params"); // you can define your status and message
return;
}
// good params, get user from database
try {
const user = await User.findById(_id)
if (!user) {
return res.status(404).send()
}
res.send(user)
} catch (error) {
res.status(500).send()
}
})
2. Use findOne() method instead of findById
If you want a simpler solution, don't use findById because the function expects a valid ObjectId. We can use findOne() method :
app.get('/users/:id', async (req, res) => {
const _id = req.params.id
try {
const user = await User.findOne({_id : _id})
if (!user) {
return res.status(404).send()
}
res.send(user)
} catch (error) {
res.status(500).send()
}
})
(IMHO, the first solution is better though..)
Some helpful link :
https://docs.mongodb.com/manual/reference/method/ObjectId/
Can I determine if a string is a MongoDB ObjectID?
https://mongoosejs.com/docs/api.html#model_Model.findOne
I am using json-server to fake the Api for the FrontEnd team.
We would like to have a feature to create the multiple objects (Eg. products) in one call.
In WebApi2 or actual RestApis, it can be done like the following:
POST api/products //For Single Creation
POST api/productCollections //For Multiple Creation
I don't know how I can achieve it by using json-server. I tried to POST the following data to api/products by using the postman, but it does not split the array and create items individually.
[
{
"id": "ff00feb6-b1f7-4bb0-b09c-7b88d984625d",
"code": "MM",
"name": "Product 2"
},
{
"id": "1f4492ab-85eb-4b2f-897a-a2a2b69b43a5",
"code": "MK",
"name": "Product 3"
}
]
It treats the whole array as the single item and append to the existing json.
Could you pls suggest how I could mock bulk insert in json-server? Or Restful Api should always be for single object manipulation?
This is not something that json-server supports natively, as far as I know, but it can be accomplished through a workaround.
I am assuming that you have some prior knowledge of node.js
You will have to create a server.js file which you will then run using node.js.
The server.js file will then make use of the json-server module.
I have included the code for the server.js file in the code snippet below.
I made use of lodash for my duplicate check. You will thus need to install lodash. You can also replace it with your own code if you do not want to use lodash, but lodash worked pretty well in my opinion.
The server.js file includes a custom post request function which accesses the lowdb instance used in the json-server instance. The data from the POST request is checked for duplicates and only new records are added to the DB where the id does not already exist. The write() function of lowdb persists the data to the db.json file. The data in memory and in the file will thus always match.
Please note that the API endpoints generated by json-server (or the rewritten endpoints) will still exist. You can thus use the custom function in conjunction with the default endpoints.
Feel free to add error handling where needed.
const jsonServer = require('json-server');
const server = jsonServer.create();
const _ = require('lodash')
const router = jsonServer.router('./db.json');
const middlewares = jsonServer.defaults();
const port = process.env.PORT || 3000;
server.use(middlewares);
server.use(jsonServer.bodyParser)
server.use(jsonServer.rewriter({
'/api/products': '/products'
}));
server.post('/api/productcollection', (req, res) => {
const db = router.db; // Assign the lowdb instance
if (Array.isArray(req.body)) {
req.body.forEach(element => {
insert(db, 'products', element); // Add a post
});
}
else {
insert(db, 'products', req.body); // Add a post
}
res.sendStatus(200)
/**
* Checks whether the id of the new data already exists in the DB
* #param {*} db - DB object
* #param {String} collection - Name of the array / collection in the DB / JSON file
* #param {*} data - New record
*/
function insert(db, collection, data) {
const table = db.get(collection);
if (_.isEmpty(table.find(data).value())) {
table.push(data).write();
}
}
});
server.use(router);
server.listen(port);
If you have any questions, feel free to ask.
The answer marked as correct didn't actually work for me. Due to the way the insert function is written, it will always generate new documents instead of updating existing docs. The "rewriting" didn't work for me either (maybe I did something wrong), but creating an entirely separate endpoint helped.
This is my code, in case it helps others trying to do bulk inserts (and modifying existing data if it exists).
const jsonServer = require('json-server');
const server = jsonServer.create()
const _ = require('lodash');
const router = jsonServer.router('./db.json');
const middlewares = jsonServer.defaults()
server.use(middlewares)
server.use(jsonServer.bodyParser)
server.post('/addtasks', (req, res) => {
const db = router.db; // Assign the lowdb instance
if (Array.isArray(req.body)) {
req.body.forEach(element => {
insert(db, 'tasks', element);
});
}
else {
insert(db, 'tasks', req.body);
}
res.sendStatus(200)
function insert(db, collection, data) {
const table = db.get(collection);
// Create a new doc if this ID does not exist
if (_.isEmpty(table.find({_id: data._id}).value())) {
table.push(data).write();
}
else{
// Update the existing data
table.find({_id: data._id})
.assign(_.omit(data, ['_id']))
.write();
}
}
});
server.use(router)
server.listen(3100, () => {
console.log('JSON Server is running')
})
On the frontend, the call will look something like this:
axios.post('http://localhost:3100/addtasks', tasks)
It probably didn't work at the time when this question was posted but now it does, call with an array on the /products endpoint for bulk insert.
I was trying to insert a record into a collection when this error was thrown. I went through the mongodb doc on insertOne and I understand that mongod will automatically add the _id when it is not specified as in my case, so I'm wondering why there is an undefined id error.
Here's the code I'm working with, first the api route and the data I'm trying to insert
app.post('/api/contacts', (req, res) => {
// retrieve the user being added in the body of the request
const user = req.body;
// obtain a reference to the contacts collection
const contactsCollection = database.collection('contacts');
// insert data into the collection
contactsCollection.insertOne(user, (err, r) => {
if (err) {
return res.status(500).json({error: 'Error inserting new record.'});
}
const newRecord = r.ops[0];
return res.status(201).json(newRecord);
});
});
The json data for inserting
{
"name": "Wes Harris",
"address": "289 Porter Crossing, Silver Spring, MD 20918",
"phone": "(862) 149-8084",
"photoUrl": "/profiles/wes-harris.jpg"
}
Database connection to the to the database hosted on mlab is successful with no errors. What could possibly be wrong here and how do I go about fixing this error?
The error message means that the object that you are passing into insertOne is undefined (and hence it can’t read the _id property of of it). You might like to look at what exactly req.body contains as that is what is passed as user. (I don’t know TypeScript but, in node/express, I have had errors like this when I didn’t set up bodyParser correctly)
Faced a similar problem. Solved and it by using body-parser and then parsing the json object being sent as follows:
const bodyParser = require('body-parser');
app.use(bodyParser.json());
// parse application/json
app.use(function (req, res) {
res.setHeader('Content-Type', 'text/plain')
res.write('you posted:\n')
res.end(JSON.stringify(req.body, null, 2))
})