String-escaping functions

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

Functions
std::string	pqxx::connection_base::esc (const char str[])
	Escape string for use as SQL string literal on this connection. More...
std::string	pqxx::connection_base::esc (const char str[], size_t maxlen)
	Escape string for use as SQL string literal on this connection. More...
std::string	pqxx::connection_base::esc (const std::string &str)
	Escape string for use as SQL string literal on this connection. More...
std::string	pqxx::connection_base::esc_raw (const unsigned char str[], size_t len)
	Escape binary string for use as SQL string literal on this connection. More...
std::string	pqxx::connection_base::unesc_raw (const std::string &text)
	Unescape binary data, e.g. from a table field or notification payload. More...
std::string	pqxx::connection_base::unesc_raw (const char *text)
	Unescape binary data, e.g. from a table field or notification payload. More...
std::string	pqxx::connection_base::quote_raw (const unsigned char str[], size_t len)
	Escape and quote a string of binary data. More...
std::string	pqxx::connection_base::quote_name (const std::string &identifier)
	Escape and quote an SQL identifier for use in a query. More...
template<typename T >
std::string	pqxx::connection_base::quote (const T &t)
	Represent object as SQL string, including quoting & escaping. More...
std::string	pqxx::connection_base::quote (const binarystring &)
std::string	pqxx::connection_base::esc_like (const std::string &str, char escape_char='\\') const
	Escape string for literal LIKE match. More...
std::string	pqxx::transaction_base::esc (const char str[]) const
	Escape string for use as SQL string literal in this transaction. More...
std::string	pqxx::transaction_base::esc (const char str[], size_t maxlen) const
	Escape string for use as SQL string literal in this transaction. More...
std::string	pqxx::transaction_base::esc (const std::string &str) const
	Escape string for use as SQL string literal in this transaction. More...
std::string	pqxx::transaction_base::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	pqxx::transaction_base::esc_raw (const std::string &) const
	Escape binary data for use as SQL string literal in this transaction. More...
std::string	pqxx::transaction_base::unesc_raw (const std::string &text) const
	Unescape binary data, e.g. from a table field or notification payload. More...
std::string	pqxx::transaction_base::unesc_raw (const char *text) const
	Unescape binary data, e.g. from a table field or notification payload. More...
template<typename T >
std::string	pqxx::transaction_base::quote (const T &t) const
	Represent object as SQL string, including quoting & escaping. More...
std::string	pqxx::transaction_base::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	pqxx::transaction_base::quote_raw (const std::string &str) const
std::string	pqxx::transaction_base::quote_name (const std::string &identifier) const
	Escape an SQL identifier for use in a query. More...
std::string	pqxx::transaction_base::esc_like (const std::string &str, char escape_char='\\') const
	Escape string for literal LIKE match. More...

Detailed Description

Function Documentation

esc() [1/6]

std::string pqxx::transaction_base::esc

(

const char

str[]

)

const

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

esc() [2/6]

std::string pqxx::transaction_base::esc	(	const char	str[],
		size_t	maxlen
	)		const

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

esc() [3/6]

std::string pqxx::transaction_base::esc

(

const std::string &

str

)

const

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

esc() [4/6]

std::string pqxx::connection_base::esc

(

const char

str[]

)

Escape string for use as SQL string literal on this connection.

esc() [5/6]

std::string pqxx::connection_base::esc	(	const char	str[],
		size_t	maxlen
	)

Escape string for use as SQL string literal on this connection.

esc() [6/6]

std::string pqxx::connection_base::esc

(

const std::string &

str

)

Escape string for use as SQL string literal on this connection.

esc_like() [1/2]

std::string pqxx::transaction_base::esc_like	(	const std::string &	str,
		char	escape_char = '\\'
	)		const

Escape string for literal LIKE match.

esc_like() [2/2]

std::string pqxx::connection_base::esc_like	(	const std::string &	str,
		char	escape_char = '\\'
	)		const

Escape string for literal LIKE match.

Use this when part of an SQL "LIKE" pattern should match only as a literal string, not as a pattern, even if it contains "%" or "_" characters that would normally act as wildcards.

The string does not get string-escaped or quoted. You do that later.

For instance, let's say you have a string name entered by the user, and you're searching a file column for items that match name followed by a dot and three letters. Even if name contains wildcard characters "%" or "_", you only want those to match literally, so "_" only matches "_" and "%" only matches a single "%".

You do that by "like-escaping" name, appending the wildcard pattern ".___", and finally, escaping and quoting the result for inclusion in your query:

tx.exec( "SELECT file FROM item WHERE file LIKE " + tx.quote(tx.esc_like(name) + ".___"));

The SQL "LIKE" operator also lets you choose your own escape character. This is supported, but must be a single-byte character.

References pqxx::internal::enc_group(), and pqxx::internal::reactivation_avoidance_exemption::reactivation_avoidance_exemption().

esc_raw() [1/3]

std::string pqxx::transaction_base::esc_raw	(	const unsigned char	data[],
		size_t	len
	)		const

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

Raw, binary data is treated differently from regular strings. Binary strings are never interpreted as text, so they may safely include byte values or byte sequences that don't happen to represent valid characters in the character encoding being used.

The binary string does not stop at the first zero byte, as is the case with textual strings. Instead, they may contain zero bytes anywhere. If it happens to contain bytes that look like quote characters, or other things that can disrupt their use in SQL queries, they will be replaced with special escape sequences.

esc_raw() [2/3]

std::string pqxx::transaction_base::esc_raw

(

const std::string &

str

)

const

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

References pqxx::transaction_base::conn(), and pqxx::connection_base::esc_raw().

esc_raw() [3/3]

std::string pqxx::connection_base::esc_raw	(	const unsigned char	str[],
		size_t	len
	)

Escape binary string for use as SQL string literal on this connection.

Referenced by pqxx::transaction_base::esc_raw().

quote() [1/3]

template<typename T >

std::string pqxx::transaction_base::quote

(

const T &

t

)

const

Represent object as SQL string, including quoting & escaping.

Nulls are recognized and represented as SQL nulls.

Referenced by pqxx::internal::basic_robusttransaction::~basic_robusttransaction().

quote() [2/3]

template<typename T >

std::string pqxx::connection_base::quote

(

const T &

t

)

Represent object as SQL string, including quoting & escaping.

Nulls are recognized and represented as SQL nulls.

References pqxx::to_string().

quote() [3/3]

std::string pqxx::connection_base::quote

(

const binarystring &

b

)

References pqxx::binarystring::data(), and pqxx::binarystring::size().

quote_name() [1/2]

std::string pqxx::transaction_base::quote_name

(

const std::string &

identifier

)

const

Escape an SQL identifier for use in a query.

Referenced by pqxx::subtransaction::subtransaction(), and pqxx::internal::basic_robusttransaction::~basic_robusttransaction().

quote_name() [2/2]

std::string pqxx::connection_base::quote_name

(

const std::string &

identifier

)

Escape and quote an SQL identifier for use in a query.

quote_raw() [1/3]

std::string pqxx::transaction_base::quote_raw	(	const unsigned char	str[],
		size_t	len
	)		const

Binary-escape and quote a binarystring for use as an SQL constant.

quote_raw() [2/3]

std::string pqxx::transaction_base::quote_raw

(

const std::string &

str

)

const

References pqxx::transaction_base::Begin(), pqxx::transaction_base::conn(), pqxx::internal::namedclass::description(), and pqxx::connection_base::quote_raw().

quote_raw() [3/3]

std::string pqxx::connection_base::quote_raw	(	const unsigned char	str[],
		size_t	len
	)

Escape and quote a string of binary data.

Referenced by pqxx::transaction_base::quote_raw().

unesc_raw() [1/4]

std::string pqxx::transaction_base::unesc_raw

(

const std::string &

text

)

const

Unescape binary data, e.g. from a table field or notification payload.

Takes a binary string as escaped by PostgreSQL, and returns a restored copy of the original binary data.

unesc_raw() [2/4]

std::string pqxx::transaction_base::unesc_raw

(

const char *

text

)

const

Unescape binary data, e.g. from a table field or notification payload.

Takes a binary string as escaped by PostgreSQL, and returns a restored copy of the original binary data.

unesc_raw() [3/4]

std::string pqxx::connection_base::unesc_raw

(

const std::string &

text

)

Unescape binary data, e.g. from a table field or notification payload.

Takes a binary string as escaped by PostgreSQL, and returns a restored copy of the original binary data.

unesc_raw() [4/4]

std::string pqxx::connection_base::unesc_raw

(

const char *

text

)

Unescape binary data, e.g. from a table field or notification payload.

Takes a binary string as escaped by PostgreSQL, and returns a restored copy of the original binary data.

References pqxx::internal::freepqmem().