MongoDB FindOne

MongoDB FindOne is a method that allows you to find the first document that matches a given query. This is a useful feature if you only need one result from your queries, instead of retrieving all the matches. In this article, we will cover how to use the FindOne method in MongoDB.

Syntax

The syntax of the FindOne method is as follows:

db.collection.findOne(query, projection)

Here, the query parameter is used to specify the document criteria to match, and the projection parameter is used to specify the fields to return in the result document.

Example

Let's consider the following example where we want to find the document of a user with the name 'John'.

const MongoClient = require('mongodb').MongoClient;

const uri = "mongodb+srv://<username>:<password>@<cluster>.mongodb.net/test?retryWrites=true&w=majority";
const client = new MongoClient(uri, { useNewUrlParser: true, useUnifiedTopology: true });

client.connect(err => {
  const collection = client.db("mydb").collection("users");
  collection.findOne({ name: "John" }, function(err, result) {
    if (err) throw err;
    console.log(result);
    client.close();
  });
});

Here, we find the document of a user with the name 'John' in the 'users' collection of the 'mydb' database. We use the callback function to handle any errors and print the result. If the document is not found, the result will be null.

Conclusion

In this article, we learned about the FindOne method in MongoDB. We covered the syntax and provided an example of how to use it to find a single document in a collection. You can use this method to simplify your queries and retrieve only the relevant data that you need.