AspNetCore.Docs/aspnetcore/tutorials/first-mongo-app.md

title	author	description	monikerRange	ms.author	ms.custom	ms.date	no-loc	uid
Create a web API with ASP.NET Core and MongoDB	prkhandelwal	This tutorial demonstrates how to create an ASP.NET Core web API using a MongoDB NoSQL database.	>= aspnetcore-2.1	scaddie	mvc, seodec18	08/17/2019	cookie Cookie Blazor Blazor Server Blazor WebAssembly Identity Let's Encrypt Razor SignalR	tutorials/first-mongo-app

Create a web API with ASP.NET Core and MongoDB

By Pratik Khandelwal and Scott Addie

::: moniker range=">= aspnetcore-3.0"

This tutorial creates a web API that performs Create, Read, Update, and Delete (CRUD) operations on a MongoDB NoSQL database.

In this tutorial, you learn how to:

[!div class="checklist"]

• Configure MongoDB
• Create a MongoDB database
• Define a MongoDB collection and schema
• Perform MongoDB CRUD operations from a web API
• Customize JSON serialization

View or download sample code (how to download)

Prerequisites

Visual Studio

• .NET Core SDK 3.0 or later
• Visual Studio 2019 with the ASP.NET and web development workload
• MongoDB

Visual Studio Code

• .NET Core SDK 3.0 or later
• Visual Studio Code
• C# for Visual Studio Code
• MongoDB

Visual Studio for Mac

• .NET Core SDK 3.0 or later
• Visual Studio for Mac version 7.7 or later
• MongoDB

---

Configure MongoDB

If using Windows, MongoDB is installed at C:\Program Files\MongoDB by default. Add C:\Program Files\MongoDB\Server\<version_number>\bin to the Path environment variable. This change enables MongoDB access from anywhere on your development machine.

Use the mongo Shell in the following steps to create a database, make collections, and store documents. For more information on mongo Shell commands, see Working with the mongo Shell.

1. Choose a directory on your development machine for storing the data. For example, C:\BooksData on Windows. Create the directory if it doesn't exist. The mongo Shell doesn't create new directories.

2. Open a command shell. Run the following command to connect to MongoDB on default port 27017. Remember to replace <data_directory_path> with the directory you chose in the previous step.

   mongod --dbpath <data_directory_path>
   

3. Open another command shell instance. Connect to the default test database by running the following command:

   mongo
   

4. Run the following in a command shell:

   use BookstoreDb
   

   If it doesn't already exist, a database named BookstoreDb is created. If the database does exist, its connection is opened for transactions.

5. Create a Books collection using following command:

   db.createCollection('Books')
   

   The following result is displayed:

   { "ok" : 1 }
   

6. Define a schema for the Books collection and insert two documents using the following command:

   db.Books.insertMany([{'Name':'Design Patterns','Price':54.93,'Category':'Computers','Author':'Ralph Johnson'}, {'Name':'Clean Code','Price':43.15,'Category':'Computers','Author':'Robert C. Martin'}])
   

   The following result is displayed:

   {
     "acknowledged" : true,
     "insertedIds" : [
       ObjectId("5bfd996f7b8e48dc15ff215d"),
       ObjectId("5bfd996f7b8e48dc15ff215e")
     ]
   }
   

   [!NOTE] The ID's shown in this article will not match the IDs when you run this sample.

7. View the documents in the database using the following command:

   db.Books.find({}).pretty()
   

   The following result is displayed:

   {
     "_id" : ObjectId("5bfd996f7b8e48dc15ff215d"),
     "Name" : "Design Patterns",
     "Price" : 54.93,
     "Category" : "Computers",
     "Author" : "Ralph Johnson"
   }
   {
     "_id" : ObjectId("5bfd996f7b8e48dc15ff215e"),
     "Name" : "Clean Code",
     "Price" : 43.15,
     "Category" : "Computers",
     "Author" : "Robert C. Martin"
   }
   

   The schema adds an autogenerated _id property of type ObjectId for each document.

The database is ready. You can start creating the ASP.NET Core web API.

Create the ASP.NET Core web API project

Visual Studio

1. Go to File > New > Project.

2. Select the ASP.NET Core Web Application project type, and select Next.

3. Name the project BooksApi, and select Create.

4. Select the .NET Core target framework and ASP.NET Core 3.0. Select the API project template, and select Create.

5. Visit the NuGet Gallery: MongoDB.Driver to determine the latest stable version of the .NET driver for MongoDB. In the Package Manager Console window, navigate to the project root. Run the following command to install the .NET driver for MongoDB:

   Install-Package MongoDB.Driver -Version {VERSION}
   

Visual Studio Code

1. Run the following commands in a command shell:

   dotnet new webapi -o BooksApi
   code BooksApi
   

   A new ASP.NET Core web API project targeting .NET Core is generated and opened in Visual Studio Code.

2. After the status bar's OmniSharp flame icon turns green, a dialog asks Required assets to build and debug are missing from 'BooksApi'. Add them?. Select Yes.

3. Visit the NuGet Gallery: MongoDB.Driver to determine the latest stable version of the .NET driver for MongoDB. Open Integrated Terminal and navigate to the project root. Run the following command to install the .NET driver for MongoDB:

   dotnet add BooksApi.csproj package MongoDB.Driver -v {VERSION}
   

Visual Studio for Mac

1. In Visual Studio for Mac earlier than version 8.6, select File > New Solution > .NET Core > App from the sidebar. In version 8.6 or later, select File > New Solution > Web and Console > App from the sidebar.
2. Select the ASP.NET Core > API C# project template, and select Next.
3. Select .NET Core 3.1 from the Target Framework drop-down list, and select Next.
4. Enter BooksApi for the Project Name, and select Create.
5. In the Solution pad, right-click the project's Dependencies node and select Add Packages.
6. Enter MongoDB.Driver in the search box, select the MongoDB.Driver package, and select Add Package.
7. Select the Accept button in the License Acceptance dialog.

---

Add an entity model

1. Add a Models directory to the project root.

2. Add a Book class to the Models directory with the following code:

   using MongoDB.Bson;
   using MongoDB.Bson.Serialization.Attributes;
   
   namespace BooksApi.Models
   {
       public class Book
       {
           [BsonId]
           [BsonRepresentation(BsonType.ObjectId)]
           public string Id { get; set; }
   
           [BsonElement("Name")]
           public string BookName { get; set; }
   
           public decimal Price { get; set; }
   
           public string Category { get; set; }
   
           public string Author { get; set; }
       }
   }
   

   In the preceding class, the Id property:

   • Is required for mapping the Common Language Runtime (CLR) object to the MongoDB collection.
   • Is annotated with [BsonId] to designate this property as the document's primary key.
   • Is annotated with [BsonRepresentation(BsonType.ObjectId)] to allow passing the parameter as type string instead of an ObjectId structure. Mongo handles the conversion from string to ObjectId.

   The BookName property is annotated with the [BsonElement] attribute. The attribute's value of Name represents the property name in the MongoDB collection.

Add a configuration model

1. Add the following database configuration values to appsettings.json:

   [!code-json]

2. Add a BookstoreDatabaseSettings.cs file to the Models directory with the following code:

   [!code-csharp]

   The preceding BookstoreDatabaseSettings class is used to store the appsettings.json file's BookstoreDatabaseSettings property values. The JSON and C# property names are named identically to ease the mapping process.

3. Add the following highlighted code to Startup.ConfigureServices:

   [!code-csharp]

   In the preceding code:

   • The configuration instance to which the appsettings.json file's BookstoreDatabaseSettings section binds is registered in the Dependency Injection (DI) container. For example, a BookstoreDatabaseSettings object's ConnectionString property is populated with the BookstoreDatabaseSettings:ConnectionString property in appsettings.json.
   • The IBookstoreDatabaseSettings interface is registered in DI with a singleton service lifetime. When injected, the interface instance resolves to a BookstoreDatabaseSettings object.

4. Add the following code to the top of Startup.cs to resolve the BookstoreDatabaseSettings and IBookstoreDatabaseSettings references:

   [!code-csharp]

Add a CRUD operations service

1. Add a Services directory to the project root.

2. Add a BookService class to the Services directory with the following code:

   [!code-csharp]

   In the preceding code, an IBookstoreDatabaseSettings instance is retrieved from DI via constructor injection. This technique provides access to the appsettings.json configuration values that were added in the Add a configuration model section.

3. Add the following highlighted code to Startup.ConfigureServices:

   [!code-csharp]

   In the preceding code, the BookService class is registered with DI to support constructor injection in consuming classes. The singleton service lifetime is most appropriate because BookService takes a direct dependency on MongoClient. Per the official Mongo Client reuse guidelines, MongoClient should be registered in DI with a singleton service lifetime.

4. Add the following code to the top of Startup.cs to resolve the BookService reference:

   [!code-csharp]

The BookService class uses the following MongoDB.Driver members to perform CRUD operations against the database:

• MongoClient: Reads the server instance for performing database operations. The constructor of this class is provided the MongoDB connection string:

  [!code-csharp]

• IMongoDatabase: Represents the Mongo database for performing operations. This tutorial uses the generic GetCollection<TDocument>(collection) method on the interface to gain access to data in a specific collection. Perform CRUD operations against the collection after this method is called. In the GetCollection<TDocument>(collection) method call:

  • collection represents the collection name.
  • TDocument represents the CLR object type stored in the collection.

GetCollection<TDocument>(collection) returns a MongoCollection object representing the collection. In this tutorial, the following methods are invoked on the collection:

• DeleteOne: Deletes a single document matching the provided search criteria.
• Find<TDocument>: Returns all documents in the collection matching the provided search criteria.
• InsertOne: Inserts the provided object as a new document in the collection.
• ReplaceOne: Replaces the single document matching the provided search criteria with the provided object.

Add a controller

Add a BooksController class to the Controllers directory with the following code:

[!code-csharp]

The preceding web API controller:

• Uses the BookService class to perform CRUD operations.
• Contains action methods to support GET, POST, PUT, and DELETE HTTP requests.
• Calls xref:System.Web.Http.ApiController.CreatedAtRoute* in the Create action method to return an HTTP 201 response. Status code 201 is the standard response for an HTTP POST method that creates a new resource on the server. CreatedAtRoute also adds a Location header to the response. The Location header specifies the URI of the newly created book.

Test the web API

1. Build and run the app.

2. Navigate to http://localhost:<port>/api/books to test the controller's parameterless Get action method. The following JSON response is displayed:

   [
     {
       "id":"5bfd996f7b8e48dc15ff215d",
       "bookName":"Design Patterns",
       "price":54.93,
       "category":"Computers",
       "author":"Ralph Johnson"
     },
     {
       "id":"5bfd996f7b8e48dc15ff215e",
       "bookName":"Clean Code",
       "price":43.15,
       "category":"Computers",
       "author":"Robert C. Martin"
     }
   ]
   

3. Navigate to http://localhost:<port>/api/books/{id here} to test the controller's overloaded Get action method. The following JSON response is displayed:

   {
     "id":"{ID}",
     "bookName":"Clean Code",
     "price":43.15,
     "category":"Computers",
     "author":"Robert C. Martin"
   }
   

Configure JSON serialization options

There are two details to change about the JSON responses returned in the Test the web API section:

• The property names' default camel casing should be changed to match the Pascal casing of the CLR object's property names.
• The bookName property should be returned as Name.

To satisfy the preceding requirements, make the following changes:

1. JSON.NET has been removed from ASP.NET shared framework. Add a package reference to Microsoft.AspNetCore.Mvc.NewtonsoftJson.

2. In Startup.ConfigureServices, chain the following highlighted code on to the AddControllers method call:

   [!code-csharp]

   With the preceding change, property names in the web API's serialized JSON response match their corresponding property names in the CLR object type. For example, the Book class's Author property serializes as Author.

3. In Models/Book.cs, annotate the BookName property with the following [JsonProperty] attribute:

   [!code-csharp]

   The [JsonProperty] attribute's value of Name represents the property name in the web API's serialized JSON response.

4. Add the following code to the top of Models/Book.cs to resolve the [JsonProperty] attribute reference:

   [!code-csharp]

5. Repeat the steps defined in the Test the web API section. Notice the difference in JSON property names.

::: moniker-end

::: moniker range="< aspnetcore-3.0"

This tutorial creates a web API that performs Create, Read, Update, and Delete (CRUD) operations on a MongoDB NoSQL database.

In this tutorial, you learn how to:

[!div class="checklist"]

• Configure MongoDB
• Create a MongoDB database
• Define a MongoDB collection and schema
• Perform MongoDB CRUD operations from a web API
• Customize JSON serialization

View or download sample code (how to download)

Prerequisites

Visual Studio

• .NET Core SDK 2.2
• Visual Studio 2019 with the ASP.NET and web development workload
• MongoDB

Visual Studio Code

• .NET Core SDK 2.2
• Visual Studio Code
• C# for Visual Studio Code
• MongoDB

Visual Studio for Mac

• .NET Core SDK 2.2
• Visual Studio for Mac version 7.7 or later
• MongoDB

---

Configure MongoDB

If using Windows, MongoDB is installed at C:\Program Files\MongoDB by default. Add C:\Program Files\MongoDB\Server\<version_number>\bin to the Path environment variable. This change enables MongoDB access from anywhere on your development machine.

Use the mongo Shell in the following steps to create a database, make collections, and store documents. For more information on mongo Shell commands, see Working with the mongo Shell.

1. Choose a directory on your development machine for storing the data. For example, C:\BooksData on Windows. Create the directory if it doesn't exist. The mongo Shell doesn't create new directories.

2. Open a command shell. Run the following command to connect to MongoDB on default port 27017. Remember to replace <data_directory_path> with the directory you chose in the previous step.

   mongod --dbpath <data_directory_path>
   

3. Open another command shell instance. Connect to the default test database by running the following command:

   mongo
   

4. Run the following in a command shell:

   use BookstoreDb
   

   If it doesn't already exist, a database named BookstoreDb is created. If the database does exist, its connection is opened for transactions.

5. Create a Books collection using following command:

   db.createCollection('Books')
   

   The following result is displayed:

   { "ok" : 1 }
   

6. Define a schema for the Books collection and insert two documents using the following command:

   db.Books.insertMany([{'Name':'Design Patterns','Price':54.93,'Category':'Computers','Author':'Ralph Johnson'}, {'Name':'Clean Code','Price':43.15,'Category':'Computers','Author':'Robert C. Martin'}])
   

   The following result is displayed:

   {
     "acknowledged" : true,
     "insertedIds" : [
       ObjectId("5bfd996f7b8e48dc15ff215d"),
       ObjectId("5bfd996f7b8e48dc15ff215e")
     ]
   }
   

   [!NOTE] The ID's shown in this article will not match the IDs when you run this sample.

7. View the documents in the database using the following command:

   db.Books.find({}).pretty()
   

   The following result is displayed:

   {
     "_id" : ObjectId("5bfd996f7b8e48dc15ff215d"),
     "Name" : "Design Patterns",
     "Price" : 54.93,
     "Category" : "Computers",
     "Author" : "Ralph Johnson"
   }
   {
     "_id" : ObjectId("5bfd996f7b8e48dc15ff215e"),
     "Name" : "Clean Code",
     "Price" : 43.15,
     "Category" : "Computers",
     "Author" : "Robert C. Martin"
   }
   

   The schema adds an autogenerated _id property of type ObjectId for each document.

The database is ready. You can start creating the ASP.NET Core web API.

Create the ASP.NET Core web API project

Visual Studio

1. Go to File > New > Project.

2. Select the ASP.NET Core Web Application project type, and select Next.

3. Name the project BooksApi, and select Create.

4. Select the .NET Core target framework and ASP.NET Core 2.2. Select the API project template, and select Create.

5. Visit the NuGet Gallery: MongoDB.Driver to determine the latest stable version of the .NET driver for MongoDB. In the Package Manager Console window, navigate to the project root. Run the following command to install the .NET driver for MongoDB:

   Install-Package MongoDB.Driver -Version {VERSION}
   

Visual Studio Code

1. Run the following commands in a command shell:

   dotnet new webapi -o BooksApi
   code BooksApi
   

   A new ASP.NET Core web API project targeting .NET Core is generated and opened in Visual Studio Code.

2. After the status bar's OmniSharp flame icon turns green, a dialog asks Required assets to build and debug are missing from 'BooksApi'. Add them?. Select Yes.

3. Visit the NuGet Gallery: MongoDB.Driver to determine the latest stable version of the .NET driver for MongoDB. Open Integrated Terminal and navigate to the project root. Run the following command to install the .NET driver for MongoDB:

   dotnet add BooksApi.csproj package MongoDB.Driver -v {VERSION}
   

Visual Studio for Mac

1. In Visual Studio for Mac earlier than version 8.6, select File > New Solution > .NET Core > App from the sidebar. In version 8.6 or later, select File > New Solution > Web and Console > App from the sidebar.
2. Select the ASP.NET Core Web API C# project template, and select Next.
3. Select .NET Core 2.2 from the Target Framework drop-down list, and select Next.
4. Enter BooksApi for the Project Name, and select Create.
5. In the Solution pad, right-click the project's Dependencies node and select Add Packages.
6. Enter MongoDB.Driver in the search box, select the MongoDB.Driver package, and select Add Package.
7. Select the Accept button in the License Acceptance dialog.

---

Add an entity model

1. Add a Models directory to the project root.

2. Add a Book class to the Models directory with the following code:

   using MongoDB.Bson;
   using MongoDB.Bson.Serialization.Attributes;
   
   namespace BooksApi.Models
   {
       public class Book
       {
           [BsonId]
           [BsonRepresentation(BsonType.ObjectId)]
           public string Id { get; set; }
   
           [BsonElement("Name")]
           public string BookName { get; set; }
   
           public decimal Price { get; set; }
   
           public string Category { get; set; }
   
           public string Author { get; set; }
       }
   }
   

   In the preceding class, the Id property:

   • Is required for mapping the Common Language Runtime (CLR) object to the MongoDB collection.
   • Is annotated with [BsonId] to designate this property as the document's primary key.
   • Is annotated with [BsonRepresentation(BsonType.ObjectId)] to allow passing the parameter as type string instead of an ObjectId structure. Mongo handles the conversion from string to ObjectId.

   The BookName property is annotated with the [BsonElement] attribute. The attribute's value of Name represents the property name in the MongoDB collection.

Add a configuration model

1. Add the following database configuration values to appsettings.json:

   [!code-json]

2. Add a BookstoreDatabaseSettings.cs file to the Models directory with the following code:

   [!code-csharp]

   The preceding BookstoreDatabaseSettings class is used to store the appsettings.json file's BookstoreDatabaseSettings property values. The JSON and C# property names are named identically to ease the mapping process.

3. Add the following highlighted code to Startup.ConfigureServices:

   [!code-csharp]

   In the preceding code:

   • The configuration instance to which the appsettings.json file's BookstoreDatabaseSettings section binds is registered in the Dependency Injection (DI) container. For example, a BookstoreDatabaseSettings object's ConnectionString property is populated with the BookstoreDatabaseSettings:ConnectionString property in appsettings.json.
   • The IBookstoreDatabaseSettings interface is registered in DI with a singleton service lifetime. When injected, the interface instance resolves to a BookstoreDatabaseSettings object.

4. Add the following code to the top of Startup.cs to resolve the BookstoreDatabaseSettings and IBookstoreDatabaseSettings references:

   [!code-csharp]

Add a CRUD operations service

1. Add a Services directory to the project root.

2. Add a BookService class to the Services directory with the following code:

   [!code-csharp]

   In the preceding code, an IBookstoreDatabaseSettings instance is retrieved from DI via constructor injection. This technique provides access to the appsettings.json configuration values that were added in the Add a configuration model section.

3. Add the following highlighted code to Startup.ConfigureServices:

   [!code-csharp]

   In the preceding code, the BookService class is registered with DI to support constructor injection in consuming classes. The singleton service lifetime is most appropriate because BookService takes a direct dependency on MongoClient. Per the official Mongo Client reuse guidelines, MongoClient should be registered in DI with a singleton service lifetime.

4. Add the following code to the top of Startup.cs to resolve the BookService reference:

   [!code-csharp]

The BookService class uses the following MongoDB.Driver members to perform CRUD operations against the database:

• MongoClient: Reads the server instance for performing database operations. The constructor of this class is provided the MongoDB connection string:

  [!code-csharp]

• IMongoDatabase: Represents the Mongo database for performing operations. This tutorial uses the generic GetCollection<TDocument>(collection) method on the interface to gain access to data in a specific collection. Perform CRUD operations against the collection after this method is called. In the GetCollection<TDocument>(collection) method call:

  • collection represents the collection name.
  • TDocument represents the CLR object type stored in the collection.

GetCollection<TDocument>(collection) returns a MongoCollection object representing the collection. In this tutorial, the following methods are invoked on the collection:

• DeleteOne: Deletes a single document matching the provided search criteria.
• Find<TDocument>: Returns all documents in the collection matching the provided search criteria.
• InsertOne: Inserts the provided object as a new document in the collection.
• ReplaceOne: Replaces the single document matching the provided search criteria with the provided object.

Add a controller

Add a BooksController class to the Controllers directory with the following code:

[!code-csharp]

The preceding web API controller:

• Uses the BookService class to perform CRUD operations.
• Contains action methods to support GET, POST, PUT, and DELETE HTTP requests.
• Calls xref:System.Web.Http.ApiController.CreatedAtRoute* in the Create action method to return an HTTP 201 response. Status code 201 is the standard response for an HTTP POST method that creates a new resource on the server. CreatedAtRoute also adds a Location header to the response. The Location header specifies the URI of the newly created book.

Test the web API

1. Build and run the app.

2. Navigate to http://localhost:<port>/api/books to test the controller's parameterless Get action method. The following JSON response is displayed:

   [
     {
       "id":"5bfd996f7b8e48dc15ff215d",
       "bookName":"Design Patterns",
       "price":54.93,
       "category":"Computers",
       "author":"Ralph Johnson"
     },
     {
       "id":"5bfd996f7b8e48dc15ff215e",
       "bookName":"Clean Code",
       "price":43.15,
       "category":"Computers",
       "author":"Robert C. Martin"
     }
   ]
   

3. Navigate to http://localhost:<port>/api/books/{id here} to test the controller's overloaded Get action method. The following JSON response is displayed:

   {
     "id":"{ID}",
     "bookName":"Clean Code",
     "price":43.15,
     "category":"Computers",
     "author":"Robert C. Martin"
   }
   

Configure JSON serialization options

There are two details to change about the JSON responses returned in the Test the web API section:

• The property names' default camel casing should be changed to match the Pascal casing of the CLR object's property names.
• The bookName property should be returned as Name.

To satisfy the preceding requirements, make the following changes:

1. In Startup.ConfigureServices, chain the following highlighted code on to the AddMvc method call:

   [!code-csharp]

   With the preceding change, property names in the web API's serialized JSON response match their corresponding property names in the CLR object type. For example, the Book class's Author property serializes as Author.

2. In Models/Book.cs, annotate the BookName property with the following [JsonProperty] attribute:

   [!code-csharp]

   The [JsonProperty] attribute's value of Name represents the property name in the web API's serialized JSON response.

3. Add the following code to the top of Models/Book.cs to resolve the [JsonProperty] attribute reference:

   [!code-csharp]

4. Repeat the steps defined in the Test the web API section. Notice the difference in JSON property names.

::: moniker-end

Add authentication support to a web API

[!INCLUDE]

Next steps

For more information on building ASP.NET Core web APIs, see the following resources:

• YouTube version of this article
• xref:web-api/index
• xref:web-api/action-return-types