pqxx::transaction< ISOLATION, READWRITE > Class Template Reference

Standard back-end transaction, templatized on isolation level. More...

#include <transaction.hxx>

Inheritance diagram for pqxx::transaction< ISOLATION, READWRITE >:

Public Member Functions
	transaction (connection &c, std::string const &tname)
	Create a transaction. More...
	transaction (connection &c)
virtual	~transaction () noexcept override
Public Member Functions inherited from pqxx::transaction_base
	transaction_base ()=delete
	transaction_base (transaction_base const &)=delete
transaction_base &	operator= (transaction_base const &)=delete
virtual	~transaction_base ()=0
void	commit ()
	Commit the transaction. More...
void	abort ()
	Abort the transaction. More...
result	exec (std::string_view query, std::string const &desc=std::string{})
	Execute query. More...
result	exec (std::stringstream const &query, std::string const &desc=std::string{})
result	exec0 (std::string const &query, std::string const &desc=std::string{})
	Execute query, which should zero rows of data. More...
row	exec1 (std::string const &query, std::string const &desc=std::string{})
	Execute query returning a single row of data. More...
result	exec_n (result::size_type rows, std::string const &query, std::string const &desc=std::string{})
	Execute query, expect given number of rows. More...
template<typename TYPE >
TYPE	query_value (std::string const &query, std::string const &desc=std::string{})
	Execute query, expecting exactly 1 row with 1 field. More...
connection &	conn () const
	The connection in which this transaction lives. More...
void	set_variable (std::string_view var, std::string_view value)
	Set session variable using SQL "SET" command. More...
std::string	get_variable (std::string_view)
	Read session variable using SQL "SHOW" command. More...
std::string	esc (char const text[]) const
	Escape string for use as SQL string literal in this transaction. More...
std::string	esc (char const text[], size_t maxlen) const
	Escape string for use as SQL string literal in this transaction. More...
std::string	esc (std::string const &text) const
	Escape string for use as SQL string literal in this transaction. More...
std::string	esc (std::string_view text) const
	Escape string for use as SQL string literal in this transaction. More...
std::string	esc_raw (unsigned char const data[], size_t len) const
	Escape binary data for use as SQL string literal in this transaction. More...
std::string	esc_raw (std::string const &) const
	Escape binary data for use as SQL string literal in this transaction. More...
std::string	unesc_raw (std::string const &text) const
	Unescape binary data, e.g. from a table field or notification payload. More...
std::string	unesc_raw (char const *text) const
	Unescape binary data, e.g. from a table field or notification payload. More...
template<typename T >
std::string	quote (T const &t) const
	Represent object as SQL string, including quoting & escaping. More...
std::string	quote_raw (unsigned char const bin[], size_t len) const
	Binary-escape and quote a binarystring for use as an SQL constant. More...
std::string	quote_raw (std::string const &bin) const
std::string	quote_name (std::string_view identifier) const
	Escape an SQL identifier for use in a query. More...
std::string	esc_like (std::string const &bin, char escape_char='\\') const
	Escape string for literal LIKE match. More...
template<typename... Args>
result	exec_params (std::string const &query, Args &&... args)
	Execute an SQL statement with parameters. More...
template<typename... Args>
row	exec_params1 (std::string const &query, Args &&... args)
template<typename... Args>
result	exec_params0 (std::string const &query, Args &&... args)
template<typename... Args>
result	exec_params_n (size_t rows, std::string const &query, Args &&... args)
template<typename... Args>
result	exec_prepared (std::string const &statement, Args &&... args)
	Execute a prepared statement, with optional arguments. More...
template<typename... Args>
result	exec_prepared (zview statement, Args &&... args)
template<typename... Args>
row	exec_prepared1 (std::string const &statement, Args &&... args)
	Execute a prepared statement, and expect a single-row result. More...
template<typename... Args>
row	exec_prepared1 (zview statement, Args &&... args)
template<typename... Args>
result	exec_prepared0 (std::string const &statement, Args &&... args)
	Execute a prepared statement, and expect a result with zero rows. More...
template<typename... Args>
result	exec_prepared0 (zview statement, Args &&... args)
template<typename... Args>
result	exec_prepared_n (result::size_type rows, std::string const &statement, Args &&... args)
	Execute a prepared statement, expect a result with given number of rows. More...
template<typename... Args>
result	exec_prepared_n (result::size_type rows, zview statement, Args &&... args)
void	process_notice (char const msg[]) const
	Have connection process a warning message. More...
void	process_notice (std::string const &msg) const
	Have connection process a warning message. More...
Public Member Functions inherited from pqxx::internal::namedclass
	namedclass (std::string_view classname)
	namedclass (std::string_view classname, std::string_view name)
	namedclass (std::string_view classname, char const name[])
	namedclass (std::string_view classname, std::string &&name)
std::string const &	name () const noexcept
	Object name, or the empty string if no name was given. More...
std::string const &	classname () const noexcept
	Class name. More...
std::string	description () const
	Combination of class name and object name; or just class name. More...

Additional Inherited Members
Protected Member Functions inherited from pqxx::internal::basic_transaction
	basic_transaction (connection &c, char const begin_command[])
Protected Member Functions inherited from pqxx::dbtransaction
	dbtransaction (connection &c)
Protected Member Functions inherited from pqxx::transaction_base
	transaction_base (connection &c)
	Create a transaction (to be called by implementation classes only). More...
void	register_transaction ()
	Register this transaction with the connection. More...
void	close () noexcept
	End transaction. To be called by implementing class' destructor. More...
result	direct_exec (std::string_view)
	Execute query on connection directly. More...
result	direct_exec (std::shared_ptr< std::string >)

Detailed Description

template<isolation_level ISOLATION = isolation_level::read_committed, write_policy READWRITE = write_policy::read_write>
class pqxx::transaction< ISOLATION, READWRITE >

Standard back-end transaction, templatized on isolation level.

This is the type you'll normally want to use to represent a transaction on the database.

Usage example: double all wages.

extern connection C;
work T(C);
try
{
  T.exec0("UPDATE employees SET wage=wage*2");
  T.commit();   // NOTE: do this inside try block
}
catch (exception const &e)
{
  cerr << e.what() << endl;
  T.abort();            // Usually not needed; same happens when T's life ends.
}

Constructor & Destructor Documentation

transaction() [1/2]

template<isolation_level ISOLATION = isolation_level::read_committed, write_policy READWRITE = write_policy::read_write>

pqxx::transaction< ISOLATION, READWRITE >::transaction ( connection &  c, std::string const &  tname  )

explicit

Create a transaction.

Parameters

c	Connection for this transaction to operate on.
tname	Optional name for transaction. Must begin with a letter and may contain letters and digits only.

transaction() [2/2]

template<isolation_level ISOLATION = isolation_level::read_committed, write_policy READWRITE = write_policy::read_write>

pqxx::transaction< ISOLATION, READWRITE >::transaction ( connection &  c )

explicit

~transaction()

template<isolation_level ISOLATION = isolation_level::read_committed, write_policy READWRITE = write_policy::read_write>

virtual pqxx::transaction< ISOLATION, READWRITE >::~transaction ( )

overridevirtualnoexcept

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The documentation for this class was generated from the following file:

• transaction.hxx