connection.hxx File Reference

#include <cstddef>
#include <ctime>
#include <functional>
#include <initializer_list>
#include <list>
#include <map>
#include <memory>
#include <string_view>
#include <tuple>
#include <utility>
#include "pqxx/errorhandler.hxx"
#include "pqxx/except.hxx"
#include "pqxx/internal/concat.hxx"
#include "pqxx/params.hxx"
#include "pqxx/separated_list.hxx"
#include "pqxx/strconv.hxx"
#include "pqxx/types.hxx"
#include "pqxx/util.hxx"
#include "pqxx/zview.hxx"
#include "pqxx/internal/ignore-deprecated-pre.hxx"
#include "pqxx/internal/ignore-deprecated-post.hxx"

Go to the source code of this file.

Classes
struct	pqxx::notification
	An incoming notification. More...
class	pqxx::connection
	Connection to a database. More...
class	pqxx::connecting
	An ongoing, non-blocking stepping stone to a connection. More...

Namespaces
	pqxx::internal
	Internal items for libpqxx' own use. Do not use these yourself.
	pqxx::internal::gate
	pqxx
	The home of all libpqxx classes, functions, templates, etc.

Typedefs
using	pqxx::table_path = std::initializer_list< std::string_view >
	Representation of a PostgreSQL table path. More...
using	pqxx::connection_base = connection

Enumerations
enum	pqxx::skip_init : int { pqxx::nothing, pqxx::openssl, pqxx::crypto }
	Flags for skipping initialisation of SSL-related libraries. More...
enum	pqxx::error_verbosity : int { pqxx::error_verbosity::terse = 0, pqxx::error_verbosity::normal = 1, pqxx::error_verbosity::verbose = 2 }
	Error verbosity levels. More...

Functions
void PQXX_COLD PQXX_LIBEXPORT	pqxx::internal::skip_init_ssl (int skips) noexcept
	Control OpenSSL/crypto library initialisation. More...
template<skip_init... SKIP>
void	pqxx::skip_init_ssl () noexcept
	Control initialisation of OpenSSL and libcrypto libraries. More...
std::string PQXX_LIBEXPORT	pqxx::encrypt_password (char const user[], char const password[])
	Encrypt a password. More...
std::string	pqxx::encrypt_password (zview user, zview password)
	Encrypt password. More...

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Class Documentation

struct pqxx::notification

An incoming notification.

PostgreSQL extends SQL with a "message bus" using the LISTEN and NOTIFY commands. In libpqxx you use connection::listen() and (optionally) transaction_base::notify().

When you receive a notification for which you have been listening, your handler receives it in the form of a notification object.

Warning

These structs are meant for extremely short lifespans: the fields reference memory that may become invalid as soon as your handler has been called.

Class Members
int	backend_pid	Process ID of the backend that sent the notification. This can be useful in situations where a multiple clients are listening on the same channel, and also send notifications on it. In those situations, it often makes sense for a client to ignore its own incoming notifications, but handle all others on the same channel in some way. To check for that, compare this process ID to the return value of the connection's backendpid().
zview	channel	Channel name. The notification logic will only pass the notification to a handler which was registered to listen on this exact name.
connection &	conn	The connection which received the notification. There will be no backend transaction active on the connection when your handler gets called, but there may be a nontransaction. (This is a special transaction type in libpqxx which does not start a transaction on the backend.)
zview	payload	Optional payload text. If the notification did not carry a payload, the string will be empty.