Reference to one row in a result. More...

#include <row.hxx>

Public Types
using	size_type = row_size_type

using	difference_type = row_difference_type

using	const_iterator = const_row_iterator

using	iterator = const_iterator

using	reference = field

using	pointer = const_row_iterator

using	const_reverse_iterator = const_reverse_row_iterator

using	reverse_iterator = const_reverse_iterator

Public Member Functions
	row () noexcept=default

	row (row &&) noexcept=default

	row (row const &) noexcept=default

row &	operator= (row const &) noexcept=default

row &	operator= (row &&) noexcept=default

Comparison
PQXX_PURE bool	operator== (row const &) const noexcept

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

const_iterator	begin () const noexcept

const_iterator	cbegin () const noexcept

const_iterator	end () const noexcept

const_iterator	cend () const noexcept

Field access
reference	front () const noexcept

reference	back () const noexcept

const_reverse_row_iterator	rbegin () const noexcept

const_reverse_row_iterator	crbegin () const noexcept

const_reverse_row_iterator	rend () const noexcept

const_reverse_row_iterator	crend () const noexcept

reference	operator[] (size_type) const noexcept

reference	operator[] (zview col_name) const

reference	at (size_type) const

reference	at (zview col_name) const

constexpr size_type	size () const noexcept

constexpr result::size_type	rownumber () const noexcept
	Row number, assuming this is a real row and not end()/rend(). More...

Column information
class	const_row_iterator

class	result

template<typename... T>
class	pqxx::internal::result_iter

class	field

result	m_result
	Result set of which this is one row. More...

result::size_type	m_index = 0
	Row number. More...

size_type	m_begin = 0
	First column in slice. This row ignores lower-numbered columns. More...

size_type	m_end = 0
	End column in slice. This row only sees lower-numbered columns. More...

size_type	column_number (zview col_name) const
	Number of given column (throws exception if it doesn't exist). More...

oid	column_type (size_type) const
	Return a column's type. More...

oid	column_type (zview col_name) const
	Return a column's type. More...

oid	column_table (size_type col_num) const
	What table did this column come from? More...

oid	column_table (zview col_name) const
	What table did this column come from? More...

size_type	table_column (size_type) const
	What column number in its table did this result column come from? More...

size_type	table_column (zview col_name) const
	What column number in its table did this result column come from? More...

constexpr result::size_type	num () const noexcept

template<typename Tuple >
void	to (Tuple &t) const
	Extract entire row's values into a tuple. More...

template<typename... TYPE>
std::tuple< TYPE... >	as () const
	Extract entire row's values into a tuple. More...

void	swap (row &) noexcept

row	slice (size_type sbegin, size_type send) const

PQXX_PURE bool	empty () const noexcept
	Is this a row without fields? Can only happen to a slice. More...

	row (result const &r, result_size_type index, size_type cols) noexcept

void	check_size (size_type expected) const
	Throw usage_error if row size is not `expected`. More...

template<typename TUPLE >
TUPLE	as_tuple () const
	Convert to a given tuple of values, don't check sizes. More...

template<typename Tuple >
void	convert (Tuple &t) const
	Convert entire row to tuple fields, without checking row size. More...

Detailed Description

Reference to one row in a result.

A row represents one row (also called a row) in a query result set. It also acts as a container mapping column numbers or names to field values (see below):

cout << row["date"].c_str() << ": " << row["name"].c_str() << endl;

pqxx::row::row

row() noexcept=default

The row itself acts like a (non-modifyable) container, complete with its own const_iterator and const_reverse_iterator.

Member Typedef Documentation

◆ const_iterator

using pqxx::row::const_iterator = const_row_iterator

◆ const_reverse_iterator

using pqxx::row::const_reverse_iterator = const_reverse_row_iterator

◆ difference_type

using pqxx::row::difference_type = row_difference_type

◆ iterator

using pqxx::row::iterator = const_iterator

◆ pointer

using pqxx::row::pointer = const_row_iterator

◆ reference

using pqxx::row::reference = field

◆ reverse_iterator

using pqxx::row::reverse_iterator = const_reverse_iterator

◆ size_type

using pqxx::row::size_type = row_size_type

Constructor & Destructor Documentation

◆ row() [1/4]

pqxx::row::row ( )

defaultnoexcept

◆ row() [2/4]

pqxx::row::row ( row && )

defaultnoexcept

◆ row() [3/4]

pqxx::row::row ( row const & )

defaultnoexcept

◆ row() [4/4]

pqxx::row::row	(	result const &	r,
		result_size_type	index,
		size_type	cols
	)

protectednoexcept

Implementation of the pqxx::result class and support classes.

pqxx::result represents the set of result rows from a database query.

See COPYING for copyright license. If you did not receive a file called COPYING with this source code, please notify the distributor of this mistake, or contact the author.

Member Function Documentation

◆ as()

template<typename... TYPE>

std::tuple<TYPE...> pqxx::row::as ( ) const

Extract entire row's values into a tuple.

Converts to the types of the tuple's respective fields.

The types must have conversions from PostgreSQL's text format defined; see Supporting additional data types.

Exceptions

usage_error If the number of columns in the row does not match the number of fields in t.

◆ as_tuple()

template<typename TUPLE >

TUPLE pqxx::row::as_tuple ( ) const

protected

Convert to a given tuple of values, don't check sizes.

We need this for cases where we have a full tuple of field types, but not a parameter pack.

◆ at() [1/2]

pqxx::field pqxx::row::at ( size_type i ) const

◆ at() [2/2]

pqxx::field pqxx::row::at ( zview col_name ) const

Address field by name.

Warning: This is much slower than indexing by number, or iterating.

◆ back()

pqxx::row::reference pqxx::row::back ( ) const

noexcept

◆ begin()

pqxx::row::const_iterator pqxx::row::begin ( ) const

noexcept

References m_begin.

◆ cbegin()

pqxx::row::const_iterator pqxx::row::cbegin ( ) const

noexcept

◆ cend()

pqxx::row::const_iterator pqxx::row::cend ( ) const

noexcept

◆ check_size()

void pqxx::row::check_size ( size_type expected ) const

protected

Throw usage_error if row size is not expected.

◆ column_number()

pqxx::row::size_type pqxx::row::column_number ( zview col_name ) const

Number of given column (throws exception if it doesn't exist).

References pqxx::result::column_number().

◆ column_table() [1/2]

pqxx::oid pqxx::row::column_table ( size_type col_num ) const

What table did this column come from?

◆ column_table() [2/2]

oid pqxx::row::column_table ( zview col_name ) const

What table did this column come from?

◆ column_type() [1/2]

pqxx::oid pqxx::row::column_type ( size_type col_num ) const

Return a column's type.

◆ column_type() [2/2]

oid pqxx::row::column_type ( zview col_name ) const

Return a column's type.

◆ convert()

template<typename Tuple >

void pqxx::row::convert ( Tuple & t ) const

protected

Convert entire row to tuple fields, without checking row size.

◆ crbegin()

pqxx::row::const_reverse_iterator pqxx::row::crbegin ( ) const

noexcept

◆ crend()

pqxx::row::const_reverse_iterator pqxx::row::crend ( ) const

noexcept

◆ empty()

bool PQXX_COLD pqxx::row::empty ( ) const

noexcept

Is this a row without fields? Can only happen to a slice.

◆ end()

pqxx::row::const_iterator pqxx::row::end ( ) const

noexcept

◆ front()

pqxx::row::reference pqxx::row::front ( ) const

noexcept

Referenced by pqxx::transaction_base::exec1(), pqxx::transaction_base::exec_params1(), and pqxx::transaction_base::exec_prepared1().

◆ num()

constexpr result::size_type pqxx::row::num ( ) const

constexprnoexcept

◆ operator!=()

bool pqxx::row::operator!= ( row const & rhs ) const

noexcept

◆ operator=() [1/2]

row& pqxx::row::operator= ( row && )

defaultnoexcept

◆ operator=() [2/2]

row& pqxx::row::operator= ( row const & )

defaultnoexcept

◆ operator==()

bool pqxx::row::operator== ( row const & rhs ) const

noexcept

◆ operator[]() [1/2]

pqxx::row::reference pqxx::row::operator[] ( size_type i ) const

noexcept

◆ operator[]() [2/2]

pqxx::row::reference pqxx::row::operator[] ( zview col_name ) const

Address field by name.

Warning: This is much slower than indexing by number, or iterating.

◆ rbegin()

pqxx::row::const_reverse_iterator pqxx::row::rbegin ( ) const

noexcept

◆ rend()

pqxx::row::const_reverse_iterator pqxx::row::rend ( ) const

noexcept

◆ rownumber()

constexpr result::size_type pqxx::row::rownumber ( ) const

constexprnoexcept

Row number, assuming this is a real row and not end()/rend().

◆ size()

constexpr size_type pqxx::row::size ( ) const

constexprnoexcept

◆ slice()

pqxx::row PQXX_COLD pqxx::row::slice	(	size_type	sbegin,
		size_type	send
	)		const

Produce a slice of this row, containing the given range of columns.

Deprecated:: I haven't heard of anyone caring about row slicing at all in at least the last 15 years. Yet it adds complexity, so unless anyone files a bug explaining why they really need this feature, I'm going to remove it. Even if they do, the feature may need an update.

The slice runs from the range's starting column to the range's end column, exclusive. It looks just like a normal result row, except slices can be empty.

References m_begin.

◆ swap()

void pqxx::row::swap ( row & rhs )

noexcept

◆ table_column() [1/2]

pqxx::row::size_type pqxx::row::table_column ( size_type col_num ) const

What column number in its table did this result column come from?

A meaningful answer can be given only if the column in question comes directly from a column in a table. If the column is computed in any other way, a logic_error will be thrown.

Parameters

col_num a zero-based column number in this result set

Returns: a zero-based column number in originating table

◆ table_column() [2/2]

size_type pqxx::row::table_column ( zview col_name ) const

What column number in its table did this result column come from?

◆ to()

template<typename Tuple >

void pqxx::row::to ( Tuple & t ) const

Extract entire row's values into a tuple.

Converts to the types of the tuple's respective fields.

The types in the tuple must have conversions from PostgreSQL's text format defined; see Supporting additional data types.

Exceptions

usage_error If the number of columns in the row does not match the number of fields in t.

Friends And Related Function Documentation

◆ const_row_iterator

friend class const_row_iterator

friend

◆ field

friend class field

friend

◆ pqxx::internal::result_iter

template<typename... T>

friend class pqxx::internal::result_iter

friend

◆ result

friend class result

friend

Member Data Documentation

◆ m_begin

size_type pqxx::row::m_begin = 0

protected

First column in slice. This row ignores lower-numbered columns.

Referenced by begin(), and slice().

◆ m_end

size_type pqxx::row::m_end = 0

protected

End column in slice. This row only sees lower-numbered columns.

◆ m_index

result::size_type pqxx::row::m_index = 0

protected

Row number.

You'd expect this to be unsigned, but due to the way reverse iterators are related to regular iterators, it must be allowed to underflow to -1.

◆ m_result

result pqxx::row::m_result

protected

Result set of which this is one row.

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

row.hxx
row.cxx

Public Types

Public Member Functions

Column information

Detailed Description

Member Typedef Documentation

◆ const_iterator

◆ const_reverse_iterator

◆ difference_type

◆ iterator

◆ pointer

◆ reference

◆ reverse_iterator

◆ size_type

Constructor & Destructor Documentation

◆ row() [1/4]

◆ row() [2/4]

◆ row() [3/4]

◆ row() [4/4]

Member Function Documentation

◆ as()

◆ as_tuple()

◆ at() [1/2]

◆ at() [2/2]

◆ back()

◆ begin()

◆ cbegin()

◆ cend()

◆ check_size()

◆ column_number()

◆ column_table() [1/2]

◆ column_table() [2/2]

◆ column_type() [1/2]

◆ column_type() [2/2]

◆ convert()

◆ crbegin()

◆ crend()

◆ empty()

◆ end()

◆ front()

◆ num()

◆ operator!=()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ operator==()

◆ operator[]() [1/2]

◆ operator[]() [2/2]

◆ rbegin()

◆ rend()

◆ rownumber()

◆ size()

◆ slice()

◆ swap()

◆ table_column() [1/2]

◆ table_column() [2/2]

◆ to()

Friends And Related Function Documentation

◆ const_row_iterator

◆ field

◆ pqxx::internal::result_iter

◆ result

Member Data Documentation

◆ m_begin

◆ m_end

◆ m_index

◆ m_result