--- title: "How to Connect C++ Programs to MariaDB" publish_date: 2021-03-18 updated_date: 2021-08-30 author: "Rob Hedgpeth" channel: - name: "Developer" url: "/ja/resources/blog/channel/developer.md" tags: - name: "C++" url: "/resources/blog/tag/c.md" - name: "Connector/C++" url: "/resources/blog/tag/connector-c.md" - name: "MariaDB" url: "/resources/blog/tag/mariadb.md" - name: "MariaDB Connector" url: "/resources/blog/tag/mariadb-connector.md" --- # How to Connect C++ Programs to MariaDB Today, we [announced the general availability of MariaDB Connector/C++](https://staging-mdb.com/resources/blog/announcing-general-availability-of-mariadb-connector-c++/). The C++ language is known for its efficiency, versatility and extensibility. In fact, it’s often used in industries like fintech and gaming where applications require predictable concurrency and latency. With MariaDB Connector/C++, developers can use the new connector within their applications to natively connect to MariaDB Server on premises and in the cloud on [MariaDB SkySQL](https://staging-mdb.com/products/skysql/). In this article I’ll be introducing you to MariaDB Connector/C++ with simple examples that demonstrate create, read, update, and delete (CRUD) interactions with data stored in MariaDB. More specifically, I’m going to walk through the process of creating a C++ console application that will allow you to perform simple operations for managing tasks. But enough talk, let’s get started! ### Downloading and Installing In order to use MariaDB Connector/C++ you need to have access to an instance of MariaDB Server. There are a variety of ways you can get started with MariaDB on your local machine, on-premises, or even in the cloud. 1. Download and install MariaDB Community Server 1. [Directly](https://staging-mdb.com/downloads/#mariadb_platform-mariadb_server) 2. [Using a Docker image](https://hub.docker.com/r/mariadb/server) 2. [Download and install MariaDB Enterprise Server ](https://staging-mdb.com/downloads/#mariadb_platform-enterprise_server) 3. [Deploy with MariaDB SkySQL, the ultimate MariaDB cloud database](https://staging-mdb.com/products/skysql/) After you’ve set up a MariaDB Server instance you can follow the steps provided within the MariaDB Enterprise documentation for [instructions on how to download and install MariaDB Connector/C++](https://staging-mdb.com/docs/appdev/connector-cpp/). ### Preparing MariaDB Server In this example, before you can use the new MariaDB C++ connector you will need to have a database and table. Using a client of your choosing, connect to your MariaDB database instance and: 1\. Create a new database and a single table that will be responsible for storing the task records. ``` CREATE DATABASE IF NOT EXISTS todo; CREATE TABLE todo.tasks (   id INT(11) unsigned NOT NULL AUTO_INCREMENT,   description VARCHAR(500) NOT NULL,   completed BOOLEAN NOT NULL DEFAULT 0,   PRIMARY KEY (id) ); ``` 2\. Create a new database user that Connector/C++ will use to connect to MariaDB. ``` CREATE USER IF NOT EXISTS app_user@localhost IDENTIFIED BY 'Password123!'; GRANT ALL PRIVILEGES ON todo.* TO app_user@localhost; ``` ### Connecting to MariaDB Server Now that you have your database instance, schema, and user set up, it’s time to jump into C++. It all starts by establishing a connection to MariaDB. Of course, to do that, you need to have included the MariaDB connector header files, specifically [conncpp.hpp](https://github.com/mariadb-corporation/mariadb-connector-cpp/blob/master/include/ConnCpp.h), at the top of the file that you’re adding your C++ code to. ``` #include ``` To establish a connection, start by retrieving a `Driver` object that can then be used, in combination with Java Database Connectivity (JDBC) configuration information, to obtain a `Connection` object. ``` // Instantiate Driver sql::Driver* driver = sql::mariadb::get_driver_instance(); // Configure Connection sql::SQLString url("jdbc:mariadb://localhost:3306/todo"); sql::Properties properties({{"user", "app_user"}, {"password", "Password123!"}}); // Establish Connection std::unique_ptr conn(driver->connect(url, properties)); ``` For more information on MariaDB’s Connector/C++’s connection functionality be sure to check out our [official enterprise documentation](https://staging-mdb.com/docs/appdev/connector-cpp/#establishing-connections). ### Adding Tasks Once you’ve obtained a `Connection` object, you’re off to the races! Using conn, from the previous section, you’re now able to execute SQL through the use of a prepared statement to insert data into MariaDB. ``` // Create a new PreparedStatement std::unique_ptr stmnt(conn->prepareStatement("insert into tasks (description) values (?)")); // Bind values to SQL statement stmnt->setString(1, description); // Execute query stmnt->executeQuery(); ``` ### Retrieving Tasks Using a very similar approach, as within the last section, you can also create a `Statement` object to retrieve and print out all of the task records within the tasks table. ``` // Create a new Statement std::unique_ptr stmnt(conn->createStatement()); // Execute query sql::ResultSet *res = stmnt->executeQuery("select * from tasks"); // Loop through and print results while (res->next()) { std::cout << "id = " << res->getInt(1); std::cout << ", description = " << res->getString(2); std::cout << ", completed = " << res->getBoolean(3) << "\n"; } ``` ### Updating Tasks You can also use a `PreparedStatement` and specifying parameters (and values) to locate and modify an existing task record. ``` // Create a new PreparedStatement std::unique_ptr stmnt(conn->prepareStatement("update tasks set completed = ? where id = ?")); // Bind values to SQL statement stmnt->setBoolean(1, completed); stmnt->setInt(2, id); // Execute query stmnt->executeQuery(); ``` ### Deleting Tasks And, of course, you also have the ability to remove data from MariaDB by using a `DELETE SQL` statement with a `PreparedStatement`, to target a specific record. ``` // Create a new PreparedStatement std::unique_ptr stmnt(conn->prepareStatement("delete from tasks where id = ?")); // Bind values to SQL statement stmnt->setInt(1, id); // Execute query stmnt->executeQuery(); ``` ### Bringing It All Together Finally, you can put everything together in one, self-contained example by copying and pasting the code below into a new file called *tasks.cpp*. The sample below combines all of the CRUD operations I’ve gone through into a collection of functions that can be executed from the *main* method. ``` #include #include #include // Delete a task record (indicated by id) void deleteTask(std::unique_ptr &conn, int id) { try { // Create a new PreparedStatement std::unique_ptr stmnt(conn->prepareStatement("delete from tasks where id = ?")); // Bind values to SQL statement stmnt->setInt(1, id); // Execute query stmnt->executeQuery(); } catch(sql::SQLException& e){ std::cerr << "Error deleting task: " << e.what() << std::endl; } } // Update the completed value of a task record (indicated by id) void updateTaskStatus(std::unique_ptr &conn, int id, bool completed) { try { // Create a new PreparedStatement std::unique_ptr stmnt(conn->prepareStatement("update tasks set completed = ? where id = ?")); // Bind values to SQL statement stmnt->setBoolean(1, completed); stmnt->setInt(2, id); // Execute query stmnt->executeQuery(); } catch(sql::SQLException& e){ std::cerr << "Error updating task status: " << e.what() << std::endl; } } // Create a new task record void addTask(std::unique_ptr &conn, std::string description) { try { // Create a new PreparedStatement std::unique_ptr stmnt(conn->prepareStatement("insert into tasks (description) values (?)")); // Bind values to SQL statement stmnt->setString(1, description); // Execute query stmnt->executeQuery(); } catch(sql::SQLException& e){ std::cerr << "Error inserting new task: " << e.what() << std::endl; } } // Print all records in tasks table void showTasks(std::unique_ptr &conn) { try { // Create a new Statement std::unique_ptr stmnt(conn->createStatement()); // Execute query sql::ResultSet *res = stmnt->executeQuery("select * from tasks"); // Loop through and print results while (res->next()) { std::cout << "id = " << res->getInt(1); std::cout << ", description = " << res->getString(2); std::cout << ", completed = " << res->getBoolean(3) << "\n"; } } catch(sql::SQLException& e){ std::cerr << "Error selecting tasks: " << e.what() << std::endl; } } // Main Process int main(int argc, char **argv){ if (argc==1){ std::cout << "Please provide an argument.\n"; } else { try { // Instantiate Driver sql::Driver* driver = sql::mariadb::get_driver_instance(); // Configure Connection sql::SQLString url("jdbc:mariadb://localhost:3306/todo"); sql::Properties properties({{"user", "app_user"}, {"password", "Password123!"}}); // Establish Connection std::unique_ptr conn(driver->connect(url, properties)); // Use arguments to determine execution next steps if (!strcmp(argv[1],"showTasks")) { showTasks(conn); } else if (!strcmp(argv[1],"addTask")) { if (argc != 3) { std::cout << "Invalid arguments"; return 1; } addTask(conn, argv[2]); } else if (!strcmp(argv[1],"updateTaskStatus")) { if (argc != 4) { std::cout << "Invalid arguments"; return 1; } updateTaskStatus(conn, atoi(argv[2]), argv[3]); } else if (!strcmp(argv[1],"deleteTask")) { if (argc != 3) { std::cout << "Invalid arguments"; return 1; } deleteTask(conn, atoi(argv[2])); } // Close Connection conn->close(); } catch(sql::SQLException& e){ std::cerr << "Error Connecting to MariaDB Platform: " << e.what() << std::endl; // Exit (Failed) return 1; } } // Exit (Success) return 0; } ``` You can also find the full source of this sample application [here](https://github.com/mariadb-corporation/dev-example-todo/tree/master/console/cpp). The source for this C++ example is contained within a [repository](https://github.com/mariadb-corporation/dev-example-todo) for an application called “TODO”, which also includes a web front-end and several other MariaDB connector integration sample applications spanning a multitude of languages. ### Running the Application Within a Linux environment, after you’ve created *tasks.cpp*, you can build an executable file, called tasks, using a C++ compiler. ``` $ g++ -o tasks tasks.cpp -std=c++11 -lmariadbcpp ``` Using the executable file you can supply various argument values to test the CRUD operations. - Inserting a new task record by supplying a value for description. ``` ./tasks addTask ‘A New Task’ ``` - Printing out all task records. ``` ./tasks showTasks ``` - Updating a task record’s completed value. Simply supply values for id and completed. ``` ./tasks updateTaskStatus 1 1 ``` - Delete a task record by supplying an id value. ``` ./tasks deleteTask 1 ``` ### Just the Beginning Hopefully, you enjoyed seeing how easy it is to get started using C++ with MariaDB. While this is a great introduction to C++ programming with MariaDB, we’ve only started to scratch the surface of what’s possible! Looking to dive deeper into MariaDB Connector/C++? Be sure to check out the [MariaDB Developer Hub](https://staging-mdb.com/developers) for even more content on the new C++ connector as well as many other MariaDB features and capabilities. Find the [MariaDB Connector/C++ enterprise documentation](https://staging-mdb.com/docs/appdev/connector-cpp/).