reference/cxx/delete_data_in_existing_hyper_file_8cpp-example.html

#include <fstream>

#include <hyperapi/hyperapi.hpp>

#include <iostream>

#include <string>


static void copy(const std::string& sourcePath, const std::string& destinationPath) {

   std::ifstream source(sourcePath, std::ios::binary);

   std::ofstream destination(destinationPath, std::ios::binary);

   destination << source.rdbuf();

   source.close();

   destination.close();

}


static void runDeleteDataInExistingHyperFile() {

   std::cout << "EXAMPLE - Delete data from an existing Hyper file" << std::endl;


   // Path to a Hyper file containing all data inserted into Customer, Product, Orders and LineItems table

   // See "insert_data_into_multiple_tables.cpp" for an example that works with the complete schema.

   const std::string pathToSourceDatabase = "data/superstore_sample.hyper";


   // Make a copy of the superstore example Hyper file.

   const std::string pathToDatabase = "data/superstore_sample_delete.hyper";

   copy(pathToSourceDatabase, pathToDatabase);


   // Starts the Hyper Process with telemetry enabled to send data to Tableau.

   // To opt out, simply set telemetry=hyperapi::Telemetry::DoNotSendUsageDataToTableau.

   {

      hyperapi::HyperProcess hyper(hyperapi::Telemetry::SendUsageDataToTableau);


      // Connect to existing Hyper file "superstore_sample_delete.hyper".

      {

         hyperapi::Connection connection(hyper.getEndpoint(), pathToDatabase);


         std::cout << "Delete all rows from customer with the name 'Dennis Kane' from table " << hyperapi::escapeName("Orders") << "." << std::endl;

         // `executeCommand` executes a SQL statement and returns the impacted row count.

         int64_t rowCount = connection.executeCommand(

            "DELETE FROM " + hyperapi::escapeName("Orders") + " WHERE " + hyperapi::escapeName("Customer ID") + " = ANY(SELECT " +

            hyperapi::escapeName("Customer ID") + " FROM " + hyperapi::escapeName("Customer") + " WHERE " + hyperapi::escapeName("Customer Name") + " = " +

            hyperapi::escapeStringLiteral("Dennis Kane") + ")");

         std::cout << "The number of deleted rows in table " << hyperapi::escapeName("Orders") << " is " << rowCount << "." << std::endl

                   << std::endl;


         std::cout << "Delete all rows from customer with the name 'Dennis Kane' from table " << hyperapi::escapeName("Customer") << "." << std::endl;

         rowCount = connection.executeCommand(

            "DELETE FROM " + hyperapi::escapeName("Customer") + " WHERE " + hyperapi::escapeName("Customer Name") + " =" +

            hyperapi::escapeStringLiteral("Dennis Kane"));


         std::cout << "The number of deleted rows in table Customer is " << rowCount << "." << std::endl;

      }

      std::cout << "The connection to the Hyper file has been closed." << std::endl;

   }

   std::cout << "The Hyper Process has been shut down." << std::endl;

}


int main() {

   try {

      runDeleteDataInExistingHyperFile();

   } catch (const hyperapi::HyperException& e) {

      std::cout << e.toString() << std::endl;

      return 1;

   }

   return 0;

}