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

#include <transaction.hxx>

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

[legend]

Public Types
using	isolation_tag = isolation_traits< ISOLATIONLEVEL >

Public Types inherited from pqxx::transaction_base
using	isolation_tag = isolation_traits< read_committed >
	If nothing else is known, our isolation level is at least read_committed. More...

Public Member Functions
	transaction (connection_base &C, const std::string &TName)
	Create a transaction. More...

	transaction (connection_base &C)

virtual	~transaction () noexcept

Public Member Functions inherited from pqxx::dbtransaction
virtual	~dbtransaction ()

Public Member Functions inherited from pqxx::transaction_base
	transaction_base ()=delete

	transaction_base (const transaction_base &)=delete

transaction_base &	operator= (const transaction_base &)=delete

virtual	~transaction_base ()=0

void	commit ()
	Commit the transaction. More...

void	abort ()
	Abort the transaction. More...

result	exec (const std::string &Query, const std::string &Desc=std::string())
	Execute query. More...

result	exec (const std::stringstream &Query, const std::string &Desc=std::string())

result	exec0 (const std::string &Query, const std::string &Desc=std::string())
	Execute query, which should zero rows of data. More...

row	exec1 (const std::string &Query, const std::string &Desc=std::string())
	Execute query returning a single row of data. More...

result	exec_n (size_t rows, const std::string &Query, const std::string &Desc=std::string())
	Execute query, expect given number of rows. More...

connection_base &	conn () const
	Connection this transaction is running in. More...

void	set_variable (const std::string &Var, const std::string &Val)
	Set session variable in this connection. More...

std::string	get_variable (const std::string &)
	Get currently applicable value of variable. More...

std::string	esc (const char str[]) const
	Escape string for use as SQL string literal in this transaction. More...

std::string	esc (const char str[], size_t maxlen) const
	Escape string for use as SQL string literal in this transaction. More...

std::string	esc (const std::string &str) const
	Escape string for use as SQL string literal in this transaction. More...

std::string	esc_raw (const unsigned char data[], size_t len) const
	Escape binary data for use as SQL string literal in this transaction. More...

std::string	esc_raw (const std::string &) const
	Escape binary data for use as SQL string literal in this transaction. More...

std::string	unesc_raw (const std::string &text) const
	Unescape binary data, e.g. from a table field or notification payload. More...

std::string	unesc_raw (const char *text) const
	Unescape binary data, e.g. from a table field or notification payload. More...

template<typename T >
std::string	quote (const T &t) const
	Represent object as SQL string, including quoting & escaping. More...

std::string	quote_raw (const unsigned char str[], size_t len) const
	Binary-escape and quote a binarystring for use as an SQL constant. More...

std::string	quote_raw (const std::string &str) const

std::string	quote_name (const std::string &identifier) const
	Escape an SQL identifier for use in a query. More...

template<typename ... Args>
result	exec_params (const std::string &query, Args &&...args)
	Execute an SQL statement with parameters. More...

template<typename ... Args>
row	exec_params1 (const std::string &query, Args &&... args)

template<typename ... Args>
result	exec_params0 (const std::string &query, Args &&...args)

template<typename ... Args>
result	exec_params_n (size_t rows, const std::string &query, Args &&...args)

internal::parameterized_invocation	parameterized (const std::string &query)
	Parameterize a statement. More...

template<typename ... Args>
result	exec_prepared (const std::string &statement, Args &&... args)
	Execute a prepared statement, with optional arguments. More...

template<typename ... Args>
row	exec_prepared1 (const std::string &statement, Args &&... args)
	Execute a prepared statement, and expect a single-row result. More...

template<typename ... Args>
result	exec_prepared0 (const std::string &statement, Args &&... args)
	Execute a prepared statement, and expect a result with zero rows. More...

template<typename ... Args>
result	exec_prepared_n (size_t rows, const std::string &statement, Args &&... args)
	Execute a prepared statement, expect a result with given number of rows. More...

prepare::invocation	prepared (const std::string &statement=std::string())
	Execute prepared statement. More...

void	process_notice (const char Msg[]) const
	Have connection process warning message. More...

void	process_notice (const std::string &Msg) const
	Have connection process warning message. More...

Public Member Functions inherited from pqxx::internal::namedclass
	namedclass (const std::string &Classname)

	namedclass (const std::string &Classname, const std::string &Name)

const std::string &	name () const noexcept
	Object name, or the empty string if no name was given. More...

const std::string &	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_base &C, const std::string &IsolationLevel, readwrite_policy)

Protected Member Functions inherited from pqxx::dbtransaction
	dbtransaction (connection_base &, const std::string &IsolationString, readwrite_policy rw=read_write)

	dbtransaction (connection_base &, bool direct=true, readwrite_policy rw=read_write)

void	start_backend_transaction ()
	Start a transaction on the backend and set desired isolation level. More...

virtual void	do_begin () override
	Sensible default implemented here: begin backend transaction. More...

virtual result	do_exec (const char Query[]) override
	Sensible default implemented here: perform query. More...

virtual void	do_abort () override
	Sensible default implemented here: abort backend transaction. More...

Protected Member Functions inherited from pqxx::transaction_base
	transaction_base (connection_base &c, bool direct=true)
	Create a transaction (to be called by implementation classes only) More...

void	Begin ()
	Begin transaction (to be called by implementing class) More...

void	End () noexcept
	End transaction. To be called by implementing class' destructor. More...

result	direct_exec (const char C[], int Retries=0)
	Execute query on connection directly. More...

void	reactivation_avoidance_clear () noexcept
	Forget about any reactivation-blocking resources we tried to allocate. More...

Static Protected Member Functions inherited from pqxx::dbtransaction
static std::string	fullname (const std::string &ttype, const std::string &isolation)

Protected Attributes inherited from pqxx::transaction_base
internal::reactivation_avoidance_counter	m_reactivation_avoidance
	Resources allocated in this transaction that make reactivation impossible. More...

Detailed Description

template<isolation_level ISOLATIONLEVEL = read_committed, readwrite_policy READWRITE = read_write>
class pqxx::transaction< ISOLATIONLEVEL, 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.

While you may choose to create your own transaction object to interface to the database backend, it is recommended that you wrap your transaction code into a transactor code instead and let the transaction be created for you.

See also: pqxx/transactor.hxx

If you should find that using a transactor makes your code less portable or too complex, go ahead, create your own transaction anyway.

Usage example: double all wages

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

Member Typedef Documentation

◆ isolation_tag

template<isolation_level ISOLATIONLEVEL = read_committed, readwrite_policy READWRITE = read_write>

using pqxx::transaction< ISOLATIONLEVEL, READWRITE >::isolation_tag = isolation_traits<ISOLATIONLEVEL>

Constructor & Destructor Documentation

◆ transaction() [1/2]

template<isolation_level ISOLATIONLEVEL = read_committed, readwrite_policy READWRITE = read_write>

pqxx::transaction< ISOLATIONLEVEL, READWRITE >::transaction	(	connection_base &	C,
		const std::string &	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 ISOLATIONLEVEL = read_committed, readwrite_policy READWRITE = read_write>

pqxx::transaction< ISOLATIONLEVEL, READWRITE >::transaction ( connection_base & C )

explicit

◆ ~transaction()

template<isolation_level ISOLATIONLEVEL = read_committed, readwrite_policy READWRITE = read_write>

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

virtualnoexcept

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

transaction.hxx

Public Types

Public Member Functions

Additional Inherited Members

Detailed Description

template<isolation_level ISOLATIONLEVEL = read_committed, readwrite_policy READWRITE = read_write> class pqxx::transaction< ISOLATIONLEVEL, READWRITE >

Member Typedef Documentation

◆ isolation_tag

Constructor & Destructor Documentation

◆ transaction() [1/2]

◆ transaction() [2/2]

◆ ~transaction()

template<isolation_level ISOLATIONLEVEL = read_committed, readwrite_policy READWRITE = read_write>
class pqxx::transaction< ISOLATIONLEVEL, READWRITE >