reference/cxx/create_hyper_file_from_csv_8cpp-example.html

#include <hyperapi/hyperapi.hpp>

#include <iostream>

#include <string>


static const hyperapi::TableDefinition customerTable{

   "Customer", // Since the table name is not prefixed with an explicit schema name, the table will reside in the default "public" namespace.

   {hyperapi::TableDefinition::Column{"Customer ID", hyperapi::SqlType::text(), hyperapi::Nullability::NotNullable},

    hyperapi::TableDefinition::Column{"Customer Name", hyperapi::SqlType::text(), hyperapi::Nullability::NotNullable},

    hyperapi::TableDefinition::Column{"Loyalty Reward Points", hyperapi::SqlType::bigInt(), hyperapi::Nullability::NotNullable},

    hyperapi::TableDefinition::Column{"Segment", hyperapi::SqlType::text(), hyperapi::Nullability::NotNullable}}};


// An example demonstrating loading data from a csv into a new Hyper file

// For more details, see https://help.tableau.com/current/api/hyper_api/en-us/docs/hyper_api_insert_csv.html

static void runCreateHyperFileFromCSV() {

   std::cout << "EXAMPLE - Load data from CSV into table in new Hyper file" << std::endl;

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


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

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

   {

      // Optional process parameters. They are documented in the Tableau Hyper documentation, chapter "Process Settings"

      // (https://help.tableau.com/current/api/hyper_api/en-us/reference/sql/processsettings.html).

      std::unordered_map<std::string, std::string> processParameters = {

         // Limits the number of Hyper event log files to two.

         {"log_file_max_count", "2"},

         // Limits the size of Hyper event log files to 100 megabytes.

         {"log_file_size_limit", "100M"}};


      hyperapi::HyperProcess hyper(hyperapi::Telemetry::SendUsageDataToTableau, "example", processParameters);

      // Creates new Hyper file "customer.hyper".

      // Replaces existing file with hyperapi::CreateMode::CreateAndReplace if it already exists.

      {

         // Optional connection parameters. They are documented in the Tableau Hyper documentation, chapter "Connection Settings"

         // (https://help.tableau.com/current/api/hyper_api/en-us/reference/sql/connectionsettings.html).

         std::unordered_map<std::string, std::string> connectionParameters = {{"lc_time", "en_US"}};


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

         const hyperapi::Catalog& catalog = connection.getCatalog();


         catalog.createTable(customerTable);


         // Using path to current file, create a path that locates CSV file packaged with these examples.

         std::string pathToCSV = "data/customers.csv";


         // Load all rows into "Customers" table from the CSV file.

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

         //

         // Note:

         // You might have to adjust the COPY parameters to the format of your specific csv file.

         // The example assumes that your columns are separated with the ',' character

         // and that NULL values are encoded via the string 'NULL'.

         // Also be aware that the `header` option is used in this example:

         // It treats the first line of the csv file as a header and does not import it.

         //

         // The parameters of the COPY command are documented in the Tableau Hyper SQL documentation

         // (https:#help.tableau.com/current/api/hyper_api/en-us/reference/sql/sql-copy.html).

         std::cout << "Issuing the SQL COPY command to load the csv file into the table. Since the first line" << std::endl;

         std::cout << "of our csv file contains the column names, we use the `header` option to skip it." << std::endl;

         int64_t rowCount = connection.executeCommand(

            "COPY " + customerTable.getTableName().toString() + " from " + hyperapi::escapeStringLiteral(pathToCSV) +

            " with (format csv, NULL 'NULL', delimiter ',', header)");


         std::cout << "The number of rows in table " << customerTable.getTableName() << " 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 {

      runCreateHyperFileFromCSV();

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

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

      return 1;

   }

   return 0;

}