Get ID of last inserted document in a mongoDB w/ Java driver

Get ID of last inserted document in a mongoDB w/ Java driver

To get the ID of the last inserted document in MongoDB using the Java driver, you can follow these steps:

  1. Insert a Document: First, insert a document into your MongoDB collection using the insertOne or insertMany method provided by the MongoCollection class.

    Here's an example of inserting a document:

    import com.mongodb.client.MongoClient; import com.mongodb.client.MongoClients; import com.mongodb.client.MongoCollection; import com.mongodb.client.MongoDatabase; import org.bson.Document; public class InsertDocumentExample { public static void main(String[] args) { // Connect to the MongoDB server MongoClient mongoClient = MongoClients.create("mongodb://localhost:27017"); // Select the database and collection MongoDatabase database = mongoClient.getDatabase("mydb"); MongoCollection<Document> collection = database.getCollection("mycollection"); // Create a document to insert Document document = new Document("name", "John").append("age", 30); // Insert the document into the collection collection.insertOne(document); // Close the MongoDB client mongoClient.close(); } }

  2. Retrieve the ID of the Last Inserted Document: After inserting the document, you can retrieve the ID of the last inserted document by accessing the _id field of the inserted document. MongoDB automatically generates a unique _id field for each inserted document.

    Here's how you can retrieve the _id of the last inserted document:

    // ... // Insert the document into the collection collection.insertOne(document); // Retrieve the ID of the last inserted document Object lastInsertedId = document.get("_id"); // Close the MongoDB client mongoClient.close(); // Print the ID System.out.println("Last Inserted ID: " + lastInsertedId);

In this code, we insert a document into the collection and then retrieve the value of the _id field from the inserted document. The _id field contains the unique identifier of the last inserted document.

Please note that the value of lastInsertedId will be of type ObjectId if you are using the default MongoDB ObjectID as the _id field. You can convert it to a string or use it as needed in your application.

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uiapplicationdelegate spacy cloudinary standard-deviation azure-pipelines uicontrolstate remote-notifications natural-join blurry one-to-many

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