Hyper API for C++ 0.0.18825
Hyper client library for C++ applications
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read_and_print_data_from_existing_hyper_file.cpp

An example of how to read and print data from an existing Hyper file.

An example of how to read and print data from an existing Hyper file.

#include <fstream>
#include <iostream>
#include <string>
#include <unordered_set>
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 runReadAndPrintDataFromExistingHyperFile() {
std::cout << "EXAMPLE - Read data from an existing Hyper file" << std::endl;
// Path to a Hyper file containing all data inserted into "Extract"."Extract" table
// See "insert_data_into_single_table.cpp" for an example that works with the complete schema.
const std::string pathToSourceDatabase = "data/superstore_sample_denormalized.hyper";
// Make a copy of the superstore example Hyper file.
const std::string pathToDatabase = "data/superstore_sample_denormalized_read.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.
{
// Connect to existing Hyper file "superstore_sample_denormalized_read.hyper".
{
hyperapi::Connection connection(hyper.getEndpoint(), pathToDatabase);
const hyperapi::Catalog& catalog = connection.getCatalog();
// The table names in the "Extract" schema.
std::unordered_set<hyperapi::TableName> tableNames = catalog.getTableNames("Extract");
for (auto& tableName : tableNames) {
hyperapi::TableDefinition tableDefinition = catalog.getTableDefinition(tableName);
std::cout << "Table " << tableName << " has qualified name: " << tableDefinition.getTableName() << std::endl;
for (auto& column : tableDefinition.getColumns()) {
std::cout << "\t Column " << column.getName() << " has type " << column.getType() << " and nullability " << column.getNullability()
<< std::endl;
}
std::cout << std::endl;
}
// Print all rows from the "Extract"."Extract" table.
hyperapi::TableName extractTable("Extract", "Extract");
std::cout << "These are all rows in the table " << extractTable.toString() << ":" << std::endl;
hyperapi::Result rowsInTable = connection.executeQuery("SELECT * FROM " + extractTable.toString());
for (const hyperapi::Row& row : rowsInTable) {
for (const hyperapi::Value& value : row) {
std::cout << value << '\t';
}
std::cout << '\n';
}
}
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 {
runReadAndPrintDataFromExistingHyperFile();
} catch (const hyperapi::HyperException& e) {
std::cout << e.toString() << std::endl;
return 1;
}
return 0;
}
The catalog class gives access to the metadata of the attached databases of a connection.
Definition Catalog.hpp:31
std::unordered_set< TableName > getTableNames(const SchemaName &schema) const
Gets the names of all tables in the given schema.
TableDefinition getTableDefinition(const TableName &tableName) const
Gets the table definition for an existing table.
Defines a Hyper connection.
Defines an exception object that is thrown on failure by the functions in the Hyper API C++ library.
std::string toString() const
Returns a formatted string containing the message and hint of the error and all causes.
Defines a Hyper process.
Base class for a result of a query.
Definition Result.hpp:325
A Row inside a chunk.
Definition Result.hpp:209
const TableName & getTableName() const noexcept
Returns the name of the table.
Represents an escaped SQL table name.
Definition TableName.hpp:15
const Name & getName() const noexcept
Definition TableName.hpp:39
A value inside a row.
Definition Result.hpp:44
The main header of the Hyper API for C++.
@ SendUsageDataToTableau
Telemetry data will be sent to tableau to help improve the Hyper API.