mirror of
https://github.com/boostorg/mysql.git
synced 2026-01-27 19:12:10 +00:00
86e0eacd6a
* SSL/TLS rework * Unified connection object * New prepared_statement::execute interface * New resultset::read_one mechanic * Unified row object * null_t type * Travis to GitHub actions migration * Integration test rework
112 lines
4.5 KiB
C++
112 lines
4.5 KiB
C++
//
|
|
// Copyright (c) 2019-2022 Ruben Perez Hidalgo (rubenperez038 at gmail dot com)
|
|
//
|
|
// Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
//
|
|
|
|
//[example_metadata
|
|
|
|
#include "boost/mysql/connection.hpp"
|
|
#include <boost/asio/ssl/context.hpp>
|
|
#include <boost/mysql.hpp>
|
|
#include <boost/asio/io_context.hpp>
|
|
#include <boost/system/system_error.hpp>
|
|
#include <iostream>
|
|
|
|
#define ASSERT(expr) \
|
|
if (!(expr)) \
|
|
{ \
|
|
std::cerr << "Assertion failed: " #expr << std::endl; \
|
|
exit(1); \
|
|
}
|
|
|
|
void main_impl(int argc, char** argv)
|
|
{
|
|
if (argc != 4)
|
|
{
|
|
std::cerr << "Usage: " << argv[0] << " <username> <password> <server-hostname>\n";
|
|
exit(1);
|
|
}
|
|
|
|
// I/O context and connection. We use SSL because MySQL 8+ default settings require it.
|
|
boost::asio::io_context ctx;
|
|
boost::asio::ssl::context ssl_ctx (boost::asio::ssl::context::tls_client);
|
|
boost::mysql::tcp_ssl_connection conn (ctx, ssl_ctx);
|
|
|
|
// Hostname resolution
|
|
boost::asio::ip::tcp::resolver resolver (ctx.get_executor());
|
|
auto endpoints = resolver.resolve(argv[3], boost::mysql::default_port_string);
|
|
|
|
// TCP and MySQL level connect
|
|
boost::mysql::connection_params params (
|
|
argv[1], // username
|
|
argv[2], // password
|
|
"boost_mysql_examples" // database to use; leave empty or omit the parameter for no database
|
|
);
|
|
conn.connect(*endpoints.begin(), params);
|
|
|
|
// Issue the query
|
|
const char* sql = R"(
|
|
SELECT comp.name AS company_name, emp.id AS employee_id
|
|
FROM employee emp
|
|
JOIN company comp ON (comp.id = emp.company_id)
|
|
)";
|
|
boost::mysql::tcp_ssl_resultset result = conn.query(sql);
|
|
|
|
/**
|
|
* Resultsets allow you to access metadata about the fields in the query
|
|
* using the fields() function, which returns a vector of field_metadata
|
|
* (one per field in the query, and in the same order as in the query).
|
|
* You can retrieve the field name, type, number of decimals,
|
|
* suggested display width, whether the field is part of a key...
|
|
*/
|
|
ASSERT(result.fields().size() == 2);
|
|
|
|
const boost::mysql::field_metadata& company_name = result.fields()[0];
|
|
ASSERT(company_name.database() == "boost_mysql_examples"); // database name
|
|
ASSERT(company_name.table() == "comp"); // the alias we assigned to the table in the query
|
|
ASSERT(company_name.original_table() == "company"); // the original table name
|
|
ASSERT(company_name.field_name() == "company_name"); // the name of the field in the query
|
|
ASSERT(company_name.original_field_name() == "name"); // the name of the physical field in the table
|
|
ASSERT(company_name.type() == boost::mysql::field_type::varchar); // we created the field as a VARCHAR
|
|
ASSERT(!company_name.is_primary_key()); // field is not a primary key
|
|
ASSERT(!company_name.is_auto_increment()); // field is not AUTO_INCREMENT
|
|
ASSERT(company_name.is_not_null()); // field may not be NULL
|
|
|
|
const boost::mysql::field_metadata& employee_id = result.fields()[1];
|
|
ASSERT(employee_id.database() == "boost_mysql_examples"); // database name
|
|
ASSERT(employee_id.table() == "emp"); // the alias we assigned to the table in the query
|
|
ASSERT(employee_id.original_table() == "employee"); // the original table name
|
|
ASSERT(employee_id.field_name() == "employee_id"); // the name of the field in the query
|
|
ASSERT(employee_id.original_field_name() == "id"); // the name of the physical field in the table
|
|
ASSERT(employee_id.type() == boost::mysql::field_type::int_); // we created the field as INT
|
|
ASSERT(employee_id.is_primary_key()); // field is a primary key
|
|
ASSERT(employee_id.is_auto_increment()); // we declared the field as AUTO_INCREMENT
|
|
ASSERT(employee_id.is_not_null()); // field cannot be NULL
|
|
|
|
// Close the connection
|
|
conn.close();
|
|
}
|
|
|
|
int main(int argc, char** argv)
|
|
{
|
|
try
|
|
{
|
|
main_impl(argc, argv);
|
|
}
|
|
catch (const boost::system::system_error& err)
|
|
{
|
|
std::cerr << "Error: " << err.what() << ", error code: " << err.code() << std::endl;
|
|
return 1;
|
|
}
|
|
catch (const std::exception& err)
|
|
{
|
|
std::cerr << "Error: " << err.what() << std::endl;
|
|
return 1;
|
|
}
|
|
}
|
|
|
|
//]
|
|
|