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This article is about performing bulk updates of documents in MongoDB using the Java driver. We will also learn how to update by adding new fields, changing the value of an existing field or array, or deleting documents.

Prerequisites

For this article, we will use the following tools that you must follow.

Batch update documents in MongoDB using Java

Bulk updates are useful when we need to update multiple documents in the database. Now, the question is, how do we update the documents?

Do we want to update by adding new fields, updating the value of an existing field or array, or deleting a document? To understand all these scenarios, let's create a collection and insert two documents.

Create a collection:

db.createCollection('supervisor');

Insert the first document:

db.supervisor.insertOne(
    {
          "firstname": "Mehvish",
          "lastname": "Ashiq",
          "gender": "Female",
          "contact" : {
              "email":"mehvishofficial@gmail.com",
              "phone" : [
                  {
                      "type" : "official",
                      "number" : "123456789"
                  },
                  {
                       "type" : "personal",
                       "number" : "124578369"
                  },
               ]
          },
          "entries" : [
              { "_id" : 1, "itemsperday" : [ 1,3,4,5,6,7 ] },
              { "_id" : 2, "itemperday" : [ 2,3,4,5,2,7 ] },
              { "_id" : 3, "itemperday" : [ 5,0,0,4,0,1 ] }
           ]
    }
);

Insert the second file:

db.supervisor.insertOne(
    {
          "firstname": "Tahir",
          "lastname": "Raza",
          "gender": "Male",
          "contact" : {
              "email":"tahirraza@gmail.com",
              "phone" : [
                  {
                      "type" : "official",
                      "number" : "123478789"
                  },
                  {
                       "type" : "personal",
                       "number" : "122378369"
                  },
               ]
          },
          "entries" : [
              { "_id" : 1, "itemsperday" : [ 4,5,6,7,4,6 ] },
              { "_id" : 2, "itemperday" : [ 2,3,2,7,5,2 ] },
              { "_id" : 3, "itemperday" : [ 5,0,0,1,0,0 ] }
           ]
    }
);

After populating the collection, you can db.supervisor.find().pretty();view the inserted documents using . We'll start with easy solutions and then move on to some tricky but interesting ones.

Use updateMany()to perform bulk updates by adding new fields to existing documents

Sample code:

//write your package where you want to save your source file
package com.voidtesting.javamongobulkupdateexample;

// import necessary libraries
import com.mongodb.BasicDBObject;
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoClient;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import org.bson.Document;

// Example_1
public class Example_1 {

    // main method
    public static void main(String[] args) {
        // Replace the connection string with your own connection string
        var uri = "mongodb://localhost:27017";

        // try block
        try ( MongoClient mongoClient = MongoClients.create(uri)) {

            // print message if connection is successfully established
            System.out.println("Connected successfully to server.");

            // get the specified database from the MongoDB server
            MongoDatabase database = mongoClient.getDatabase("bulkUpdate");

            // get the specified collection from the selected database
            MongoCollection<Document> collection = database.getCollection("supervisor");

            // update documents by adding a new field and its value
            collection.updateMany(new BasicDBObject(),
                    new BasicDBObject("$set",
                    new BasicDBObject("status", "Good")));

            // print a new line
            System.out.println();

            // iterate over all documents of the selected collection
            // to print in Java IDE
            collection.find().forEach(doc -> {
                System.out.println(doc.toBsonDocument());
                System.out.println();
            });// end forEach

        } // end try block

        // print error if unable to execute a command
        catch (MongoException error) {
            System.err.println("An error occurred while running a command: " + error);
        }// end catch block

    }// end main method
}//end Example_1

Output:

{
    "_id": {"$oid": "62a866e592fd89ad9c4932ed"},
    "firstname": "Mehvish",
    "lastname": "Ashiq",
    "gender": "Female",
    "contact": {
        "email": "mehvishofficial@gmail.com",
        "phone": [
            { "type": "official", "number": "123456789"},
            {"type": "personal", "number": "124578369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [1.0, 3.0, 4.0, 5.0, 6.0, 7.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 4.0, 5.0, 2.0, 7.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 4.0, 0.0, 1.0]}
     ],
     "status": "Good"
}

{
    "_id": {"$oid": "62a8670192fd89ad9c4932ee"},
    "firstname": "Tahir",
    "lastname": "Raza",
    "gender": "Male",
    "contact": {
        "email": "tahirraza@gmail.com",
        "phone": [
            {"type": "official", "number": "123478789"},
            {"type": "personal", "number": "122378369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [4.0, 5.0, 6.0, 7.0, 4.0, 6.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 2.0, 7.0, 5.0, 2.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 1.0, 0.0, 0.0]}
     ],
     "status": "Good"
}

We have formatted the output for you (as shown above), but you will see one document per line on the IDE. We can also db.supervisor.find().pretty();view the updated documents on the mongo shell using .

For this sample code, we use updateMany()the update method of the mongo collection object, which accepts filtera query and updatestatement to update the matching documents. Here, instead of filtering the documents, we add a statusnew field called update to all the existing documents (see the output given above).

updateMany()Perform a batch update of existing fields in multiple documents matching the filter using

Sample code:

//write your package where you want to save your source file
package com.voidtesting.javamongobulkupdateexample;

// import necessary libraries
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoClient;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import static com.mongodb.client.model.Filters.eq;
import static com.mongodb.client.model.Updates.combine;
import static com.mongodb.client.model.Updates.set;
import org.bson.Document;

// Example_2
public class Example_2 {

    // main method
    public static void main(String[] args) {
        // Replace the connection string with your own connection string
        var uri = "mongodb://localhost:27017";

        // try block
        try ( MongoClient mongoClient = MongoClients.create(uri)) {

            // print message if connection is successfully established
            System.out.println("Connected successfully to server.");

            // get the specified database from the MongoDB server
            MongoDatabase database = mongoClient.getDatabase("bulkUpdate");

            // get the specified collection from the selected database
            MongoCollection<Document> collection = database.getCollection("supervisor");

            // update the filtered documents by updating the existing field
            collection.updateMany(eq("gender", "Female"),combine(set("gender", "F")));
            collection.updateMany(eq("gender", "Male"),combine(set("gender", "M")));

            System.out.println();
            // iterate over all documents of the selected collection
            // to print in Java IDE
            collection.find().forEach(doc -> {
                System.out.println(doc.toBsonDocument());
                System.out.println();
            });// end forEach

        } // end try block

        // print error if unable to execute a command
        catch (MongoException error) {
            System.err.println("An error occurred while running a command: " + error);
        }// end catch block

    }// end main method
}//end Example_2

Output:

{
    "_id": {"$oid": "62a866e592fd89ad9c4932ed"},
    "firstname": "Mehvish",
    "lastname": "Ashiq",
    "gender": "F",
    "contact": {
        "email": "mehvishofficial@gmail.com",
        "phone": [
            { "type": "official", "number": "123456789"},
            {"type": "personal", "number": "124578369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [1.0, 3.0, 4.0, 5.0, 6.0, 7.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 4.0, 5.0, 2.0, 7.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 4.0, 0.0, 1.0]}
     ],
     "status": "Good"
}

{
    "_id": {"$oid": "62a8670192fd89ad9c4932ee"},
    "firstname": "Tahir",
    "lastname": "Raza",
    "gender": "M",
    "contact": {
        "email": "tahirraza@gmail.com",
        "phone": [
            {"type": "official", "number": "123478789"},
            {"type": "personal", "number": "122378369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [4.0, 5.0, 6.0, 7.0, 4.0, 6.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 2.0, 7.0, 5.0, 2.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 1.0, 0.0, 0.0]}
     ],
     "status": "Good"
}

This code example is similar to the previous one, but we are updating the value of a specific field in all documents that match the filter.

We use updateMany()to perform a bulk update on all documents genderwhere equal to Femaleand genderequal to . We change and to and , respectively .Male"gender": "Female""gender": "Male""gender":"F""gender":"M"

So far, we have seen how to use updateMany()the method to add new fields or update the value of existing fields at the first level. Next, we will learn how to use updateMany()to perform a bulk update of embedded documents that satisfy a filter query.

updateMany()Perform a batch update of embedded documents matching the filter using

Sample code:

//write your package where you want to save your source file
package com.voidtesting.javamongobulkupdateexample;

// import necessary libraries
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoClient;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.model.UpdateOptions;
import org.bson.Document;
import org.bson.conversions.Bson;

// Example_3
public class Example_3 {

    // main method
    public static void main(String[] args) {
        // Replace the connection string with your own connection string
        var uri = "mongodb://localhost:27017";

        // try block
        try ( MongoClient mongoClient = MongoClients.create(uri)) {
            // print message if connection is successfully established
            System.out.println("Connected successfully to server.");

            // get the specified database from the MongoDB server
            MongoDatabase database = mongoClient.getDatabase("bulkUpdate");

            // get the specified collection from the selected database
            MongoCollection<Document> collection = database.getCollection("supervisor");
            // filter
            Bson where = new Document().append("contact.phone.type", "official");
            // update
            Bson update = new Document().append("contact.phone.$.type", "assistant");
            // set
            Bson set = new Document().append("$set", update);

            // update collection
            collection.updateMany(where, set, new UpdateOptions());


            // iterate over all documents of the selected collection
            // to print in Java IDE
            collection.find().forEach(doc -> {
                System.out.println(doc.toBsonDocument());
                System.out.println();
            }); // end forEach

        } // end try block

        // print error if unable to execute a command
        catch (MongoException error) {
            System.err.println("An error occurred while running a command: " + error);
        }// end catch block

    }// end main method
}//end Example_3

Output:

{
    "_id": {"$oid": "62a866e592fd89ad9c4932ed"},
    "firstname": "Mehvish",
    "lastname": "Ashiq",
    "gender": "F",
    "contact": {
        "email": "mehvishofficial@gmail.com",
        "phone": [
            { "type": "assistant", "number": "123456789"},
            {"type": "personal", "number": "124578369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [1.0, 3.0, 4.0, 5.0, 6.0, 7.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 4.0, 5.0, 2.0, 7.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 4.0, 0.0, 1.0]}
     ],
     "status": "Good"
}

{
    "_id": {"$oid": "62a8670192fd89ad9c4932ee"},
    "firstname": "Tahir",
    "lastname": "Raza",
    "gender": "M",
    "contact": {
        "email": "tahirraza@gmail.com",
        "phone": [
            {"type": "assistant", "number": "123478789"},
            {"type": "personal", "number": "122378369"}
         ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [4.0, 5.0, 6.0, 7.0, 4.0, 6.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 2.0, 7.0, 5.0, 2.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 1.0, 0.0, 0.0]}
     ],
     "status": "Good"
}

In this Java program, we use updateMany()the method to perform a batch update on the embedded documents that match the filter query.

Here, we update contact.phone.typethe value of from to . To access the array of documents, we use the positional operator ( ) to update the first array value that satisfies the filter query.officialassistant$

When using the positional operator, we can also specify which array elements should be updated. We can specify the first, all, or a specific array element to be updated.

To specify an array element through the positional operator, we use dot notation, a BSONproperty access syntax for navigating an object. We use the positional operator in the following ways to update the first, all, or a specific array element.

Use bulkWrite()the API to update existing documents that match a filter query

Sample code:

//write your package where you want to save your source file
package com.voidtesting.javamongobulkupdateexample;

// import necessary libraries
import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoClient;
import com.mongodb.MongoException;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.model.DeleteOneModel;
import com.mongodb.client.model.UpdateManyModel;
import com.mongodb.client.model.WriteModel;
import java.util.ArrayList;
import java.util.List;
import org.bson.Document;

// Example_4
public class Example_4 {

    // main method
    public static void main(String[] args) {
        // Replace the connection string with your own connection string
        var uri = "mongodb://localhost:27017";

        // try block
        try ( MongoClient mongoClient = MongoClients.create(uri)) {
            // print message if connection is successfully established
            System.out.println("Connected successfully to server.");

            // get the specified database from the MongoDB server
            MongoDatabase database = mongoClient.getDatabase("bulkUpdate");

            // get the specified collection from the selected database
            MongoCollection<Document> collection = database.getCollection("supervisor");

            // create object
            List<WriteModel<Document>> writes = new ArrayList<>();

            // delete the document matching the filter
            writes.add(new DeleteOneModel<>(new Document("firstname", "Tahir")));

            // update document matching the filter
            writes.add(new UpdateManyModel<>(
                    new Document("status", "Good"), // filter
                    new Document("$set", new Document("status", "Excellent")) // update
            ));

            // bulk write
            collection.bulkWrite(writes);

            // iterate over all documents of the selected collection
            // to print in Java IDE
            collection.find().forEach(doc -> {
                System.out.println(doc.toBsonDocument());
                System.out.println();
            });// end forEach

        } // end try block
        catch (MongoException me) {
            System.err.println("An error occurred while running a command: " + me);
        }// end catch block
    }// end main method

}// end Example_4

Output:

{
    "_id": {"$oid": "62a866e592fd89ad9c4932ed"},
    "firstname": "Mehvish",
    "lastname": "Ashiq",
    "gender": "F",
    "contact": {
        "email": "mehvishofficial@gmail.com",
        "phone": [
            {"type": "assistant", "number": "123456789"},
            {"type": "personal", "number": "124578369"}
        ]
     },
     "entries": [
         {"_id": 1.0, "itemsperday": [1.0, 3.0, 4.0, 5.0, 6.0, 7.0]},
         {"_id": 2.0, "itemperday": [2.0, 3.0, 4.0, 5.0, 2.0, 7.0]},
         {"_id": 3.0, "itemperday": [5.0, 0.0, 0.0, 4.0, 0.0, 1.0]}
     ],
     "status": "Excellent"
}

In this example, we bulkWrite()perform multiple operations (delete and update) at once using the API. DeleteOneModel()for deleting documents matching the filter, while we use for UpdateManyModel()updating the value of an existing field in all documents matching the filter.