Hello World

      +
      Install, connect, try. A quick start guide to get you up and running with Couchbase and the C++ SDK.

      Couchbase has a simple interface for creating and modifying records in a document, based upon the collection into which the documents are organized. You can read more about data modeling below, but first let’s look at those data operations, and installing the C++ SDK.

      Creating a new database entry with the C++ SDK, using upsert()
      auto collection = cluster.bucket(bucket_name).scope(scope_name).collection(collection_name);
      
      const std::string document_id{ "minimal_example" };
      const tao::json::value basic_doc{
              { "a", 1.0 },
              { "b", 2.0 },
      };
      
      auto [err, res] = collection.upsert(document_id, basic_doc, {}).get();
      if (err) {
          fmt::println("Unable to perform upsert: {}", err);
      } else {
          fmt::println("id: {}, CAS: {}", document_id, res.cas().value());
      }

      upsert inserts (creates) the document if it does not exist, or replaces it if it does. We’ll explore creating and retrieving data records in more detail below, after walking through a quick installation.

      Before You Start

      Couchbase Capella, our Database-as-a-Service, lets you get on with what matters, while we take care of the administration for you. Alternately, if you need to control every aspect of deployment — or just want to run the Server in a VM on your laptop — there are several self-managed options available:

      • Couchbase Capella

      • Self-Managed Couchbase Server

      If you haven’t already got a cluster set up, the easiest route is to sign up to Couchbase Capella and deploy a free tier operational cluster, then come back to this page. Make a note of the endpoint to connect to, and remember the credentials for the user that you set up.

      Install Couchbase Server locally, or in your private Cloud:

      For the example code below to run, you’ll need the username and password of the Administrator user that you create, and the IP address of at least one of the nodes of the cluster.

      Prerequisites

      Check that you have the dependencies installed:

      • C++ 17 compiler

      • CMake version 3.19 or newer

      Supprted Operating Systems are listed on the compatibility page.

      The code examples also assume:

      • Couchbase Capella

      • Self-Managed Couchbase Server

      • You have signed up to Couchbase Capella.

      • You have created your own bucket, or loaded the Travel Sample dataset. Note, the Travel Sample dataset is installed automatically when deploying a Capella free tier cluster.

      • A user is created with permissions to access the cluster (at least Application Access permissions). See the Capella connection page for more details.

      Couchbase Capella uses Roles to control user access to cluster resources. For the purposes of this guide, you can use the Organization Owner role automatically assigned to your account during installation of the Capella cluster. In production, Couchbase strongly recommends setting up users with more granular access roles as a best practice for data security.
      • Couchbase Server is installed and accessible locally.

      • You have created your own bucket, or loaded the Travel Sample dataset using the Web interface.

      • A user is created with permissions to access your cluster (at least Application Access permissions). See Manage Users, Groups and Roles for more details.

      Couchbase Server uses Role-Based Access Control (RBAC) to control access to cluster resources. In this guide we suggest using the Full Admin role created during setup of your local Couchbase Server cluster. In production, Couchbase strongly recommends setting up users with more granular access roles as a best practice for data security.

      Installation

      More details of the installation process are in the full installation guide.

      CPM.cmake is the recommended way to include the library in your project. You need to include the following command in your CMakeLists.txt.

      CPMAddPackage(
        NAME
        couchbase_cxx_client
        GIT_TAG
        1.0.3
        VERSION
        1.0.3
        GITHUB_REPOSITORY
        "couchbase/couchbase-cxx-client"
        OPTIONS
        "COUCHBASE_CXX_CLIENT_STATIC_BORINGSSL ON")

      IDE Plugins

      To make development easier, Couchbase plugins are available for VSCode and the IntelliJ family of IDEs and editors. For links and more information on these and other integrations across the C++ ecosystem, check out the Integrations & Ecosystem page.

      Connect to your Database

      Connect to your Couchbase Capella operational cluster (or your local Couchbase Cluster, if you are trying out self-managed Couchbase).

      • Couchbase Capella

      • Self-Managed Couchbase Server

      auto options = couchbase::cluster_options(username, password);
      options.apply_profile("wan_development");
      
      auto [err, cluster] = couchbase::cluster::connect(connection_string, options).get();
      
      if (err) {
          fmt::println("Unable to connect to the cluster: {}", err);
      } else {
          // Application code here
      }

      Note, the client certificate for connecting to a Capella cluster is included in the SDK installation.

      couchbase::cluster_options options(username, password);
      
      auto [err, cluster] = couchbase::cluster::connect(connection_string, options).get();
      if (err) {
          fmt::println("Unable to connect to the cluster: {}", err);
      } else {
          // Application code here
      }

      For a deeper look at connection options, read Managing Connections.

      The connection code for getting started uses the Administrator password that you were given during set up. In any production app you should create a role restricted to the permissions needed for your app — more on this in the Security documentation.

      Create, Read, Update, Delete

      Couchbase documents are organized into buckets, scopes, and collections. CRUD operations — Create, Read, Update, Delete — can be performed upon documents in a collection.

      Insert (Create) and Upsert

      insert and upsert will both create a new document. The difference between the two is that if a document with that key already exists, the insert operation will fail, returning a document_exists error — while the upsert operation will succeed, replacing the content.

      Get (Read)

      The get method reads a document from a collection. If the collection does not have a document with this ID, the get method also returns a document_not_found error.

      const std::string document_id{ "minimal_example" };
      
      auto collection = cluster.bucket(bucket_name).scope(scope_name).collection(collection_name);
      
      auto [err, res] = collection.get(document_id).get();
      
      if (err) {
          fmt::println("Unable to perform get: {}", err);
      } else {
          std::cout << "id: " << document_id << ", result: " << res.content_as<tao::json::value>() << "\n";
      }

      Replace (Update) and Overloads

      The replace method updates the value of an existing document
      auto collection = cluster.bucket(bucket_name).scope(scope_name).collection(collection_name);
      
      const std::string document_id{ "minimal_example" };
      const tao::json::value basic_doc{
              { "a", 1.0 },
              { "b", 2.0 },
      };
      
      auto [err, res] = collection.replace(document_id, basic_doc).get();
      if (err) {
          fmt::println("Unable to perform replace: {}", err);
      } else {
          fmt::println("id: {}, CAS: {}", document_id, res.cas().value());
      }
      When you replace a document, it’s usually good practice to use optimistic locking. Otherwise, changes might get lost if two people change the same document at the same time.

      Remove (Delete)

      The remove method deletes a document from a collection:

      auto collection = cluster.bucket(bucket_name).scope(scope_name).collection(collection_name);
      
      const std::string document_id{ "minimal_example" };
      
      auto [err, res] = collection.remove(document_id).get();
      if (err) {
          fmt::println("Unable to perform remove: {}", err);
      } else {
          fmt::println("id: {}, CAS: {}", document_id, res.cas().value());
      }

      Data Modeling

      Documents are organized into collections — collections of documents that belong together. You get to decide what it means to "belong." Developers usually put documents of the same type in the same collection.

      For example, imagine you have two types of documents: customers and invoices. You could put the customer documents in a collection called customers, and the invoice documents in a collection called invoices.

      Each document belongs to exactly one collection. A document’s ID is unique within the collection.

      Different scopes can hold collections with different names. There is no relationship between collections in different scopes. Each collection belongs to just one scope and a collection’s name is unique within the scope.

      More details can be found on the Data Model page.

      What Next?

      Next Steps