Create C# .Net Application Using Mongo Database

using MongoDB.Driver;
using MongoDB.Bson;
class Program
{
    static void Main(string[] args)
    {
        // Connection string and database name
        string connectionString = "mongodb://localhost:27017";
        string dbName = "mydatabase";
        // Create a MongoDB client
        MongoClient client = new MongoClient(connectionString);
        // Get a reference to the database
        IMongoDatabase database = client.GetDatabase(dbName);
        // Access a collection
        IMongoCollection<BsonDocument> collection = database.GetCollection<BsonDocument>("mycollection");
        // Insert a document
        BsonDocument document = new BsonDocument
        {
            { "name", "John" },
            { "age", 30 }
        };
        collection.InsertOne(document);
        // Query the collection
        var result = collection.Find(new BsonDocument("name", "John")).ToList();
        foreach (var doc in result)
        {
            Console.WriteLine(doc.ToJson());
        }
    }
}

var mongo = new Mongo();
mongo.Connect();
var db = mongo.getDB("testmongo");

var mongo = new Mongo();
mongo.Connect();
// Create or access a database named "testmongo" under the "c:\Data\db" folder.
var db = mongo.getDB("testmongo");

var categorylist = db.GetCollection("studcategories");
var category = new Document();
category["Name"] = "shirsendu nandi";
category["Id"] = "20";
category["Address"] = "bangalore";
categorylist.Insert(category);
Console.WriteLine("Total number of data is: " + categorylist.Count());

db.GetCollection ("subcategories");" means it will create a collection name "subcategories" under the "testmongo" database.

After that, we create the variable of the document (e.g.: table in SQL server).

Now we are assigning the the variable with name, ID, and age.

Example

category["Name"] = "shirsendu Nandi";

Here, the "Name" is the key value of the document, and the "category ["Name"]" is the field.

You can consider that to be like a "Dictionary" or "Hashtable" in .Net collection classes.

Now we are saving the category value in the mongo database by writing this code.

categorylist.Insert(category);

We also get the total count of the records using "categorylist. Count ());"

Now press F5. Your record has been stored in the mongo db. To see that go to the "c:\Data\db" folder. You will see "testmongo. ns" has been created just like Figure 2 (marked with red). By default, the size of the database will be 16MB. It will increase automatically according to the data. But for 32-bit Windows, the maximum memory capacity will be 2 GB.

Figure.2

Step 3. Now we have to retrieve the data from the "subcategories" and display it.

For that, we have to write the code shown below.

var categories = db.GetCollection("studcategories").FindAll().Documents;
foreach (var lstcategory in categories)
{
    Console.WriteLine(lstcategory["Name"]);
    Console.WriteLine(lstcategory["Id"]);
    Console.WriteLine(lstcategory["Address"]);
}

Here first, we find all the records from the documents of "subcategories" by using "FindAll(). Documents;".

After that, we loop through each "category" and display the records.

So the complete code is.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using MongoDB.Driver;
using MongoDB.Driver.Bson;
namespace mongodbconsoleapplication
{
    class Program
    {
        static void Main(string[] args)
        {
            var mongo = new Mongo();
            mongo.Connect();
            var db = mongo.getDB("testmongo");
            var categorylist = db.GetCollection("subcategories");
            var category = new Document();
            category["Name"] = "shirsendu nandi";
            category["Id"] = "20";
            category["Adress"] = "bangalore";
            categorylist.Insert(category);
            Console.WriteLine("Total number of data is: " + categorylist.Count());
            var categories = db.GetCollection("studcategories").FindAll().Documents;
            foreach (var lstcategory in categories)
            {
                Console.WriteLine(lstcategory["Name"]);
                Console.WriteLine(lstcategory["Id"]);
                Console.WriteLine(lstcategory["Adress"]);
            }
            Console.ReadLine();
        }
    }
}

Now run the application; it will look like the figure shown below.

Conclusion

So in this article, I have described how to save and fetch data from a mongo db using C# .NET.