Classes
class	pqxx::binarystring
	Binary data corresponding to PostgreSQL's "BYTEA" binary-string type. More...

Functions
template<typename... ARGS>
auto	pqxx::transaction_base::esc (ARGS &&...args) const
	Escape string for use as SQL string literal in this transaction.

Detailed Description

Class Documentation

◆ pqxx::binarystring

class pqxx::binarystring

Binary data corresponding to PostgreSQL's "BYTEA" binary-string type.

Deprecated:: Use bytes and bytes_view for binary data. In C++20 or better, any contiguous_range of std::byte will do.

This class represents a binary string as stored in a field of type bytea.

Internally a binarystring is zero-terminated, but it may also contain null bytes, they're just like any other byte value. So don't assume that it's safe to treat the contents as a C-style string.

The binarystring retains its value even if the result it was obtained from is destroyed, but it cannot be copied or assigned.

To include a binarystring value in an SQL query, escape and quote it using the transaction's quote_raw function.

Warning: This class is implemented as a reference-counting smart pointer. Copying, swapping, and destroying binarystring objects that refer to the same underlying data block is not thread-safe. If you wish to pass binarystrings around between threads, make sure that each of these operations is protected against concurrency with similar operations on the same object, or other objects pointing to the same data block.

Public Types
using	char_type = unsigned char

using	value_type = char_type

using	size_type = std::size_t

using	difference_type = long

using	const_reference = value_type const &

using	const_pointer = value_type const *

using	const_iterator = const_pointer

using	const_reverse_iterator = std::reverse_iterator< const_iterator >

Public Member Functions
	binarystring (binarystring const &)=default

	binarystring (field const &)
	Read and unescape bytea field.

	binarystring (std::string_view)
	Copy binary data from std::string_view on binary data.

	binarystring (void const *, std::size_t)
	Copy binary data of given length straight out of memory.

	binarystring (std::shared_ptr< value_type > ptr, size_type size)
	Efficiently wrap a buffer of binary data in a `binarystring`.

size_type	size () const noexcept
	Size of converted string in bytes.

size_type	length () const noexcept
	Size of converted string in bytes.

bool	empty () const noexcept

const_iterator	begin () const noexcept

const_iterator	cbegin () const noexcept

const_iterator	end () const noexcept

const_iterator	cend () const noexcept

const_reference	front () const noexcept

const_reference	back () const noexcept

const_reverse_iterator	rbegin () const

const_reverse_iterator	crbegin () const

const_reverse_iterator	rend () const

const_reverse_iterator	crend () const

value_type const *	data () const noexcept
	Unescaped field contents.

const_reference	operator[] (size_type i) const noexcept

PQXX_PURE bool	operator== (binarystring const &) const noexcept

bool	operator!= (binarystring const &rhs) const noexcept

binarystring &	operator= (binarystring const &)

const_reference	at (size_type) const
	Index contained string, checking for valid index.

void	swap (binarystring &)
	Swap contents with other binarystring.

char const *	get () const noexcept
	Raw character buffer (no terminating zero is added).

std::string_view	view () const noexcept
	Read contents as a std::string_view.

std::string	str () const
	Read as regular C++ string (may include null characters).

std::byte const *	bytes () const
	Access data as a pointer to `std::byte`.

pqxx::bytes_view	bytes_view () const
	Read data as a `bytes_view`.

Constructor & Destructor Documentation

◆ binarystring() [1/2]

pqxx::binarystring::binarystring ( field const & F )

explicit

Read and unescape bytea field.

The field will be zero-terminated, even if the original bytea field isn't.

Parameters

F	the field to read; must be a bytea field

◆ binarystring() [2/2]

pqxx::binarystring::binarystring ( std::string_view s )

explicit

Copy binary data from std::string_view on binary data.

This is inefficient in that it copies the data to a buffer allocated on the heap.

Member Function Documentation

◆ get()

char const * pqxx::binarystring::get ( ) const

inlinenoexcept

Raw character buffer (no terminating zero is added).

Warning: No terminating zero is added! If the binary data did not end in a null character, you will not find one here.

◆ str()

std::string pqxx::binarystring::str ( ) const

Read as regular C++ string (may include null characters).

This creates and returns a new string object. Don't call this repeatedly; retrieve your string once and keep it in a local variable. Also, do not expect to be able to compare the string's address to that of an earlier invocation.

Function Documentation

◆ esc()

template<typename... ARGS>

auto pqxx::transaction_base::esc ( ARGS &&... args ) const

inline

Escape string for use as SQL string literal in this transaction.

Use these when writing SQL queries that incorporate C++ values as SQL constants.

The functions you see here are just convenience shortcuts to the same functions on the connection object.

Classes

Functions