Reading column values

Reads values from columns of the current rowset. More...

Functions
template<class T >
void	nanodbc::result::get_ref (short column, T &result) const
	Gets data from the given column of the current rowset.
template<class T >
void	nanodbc::result::get_ref (short column, T const &fallback, T &result) const
	Gets data from the given column of the current rowset.
template<class T >
void	nanodbc::result::get_ref (string const &column_name, T &result) const
	Gets data from the given column by name of the current rowset.
template<class T >
void	nanodbc::result::get_ref (string const &column_name, T const &fallback, T &result) const
	Gets data from the given column by name of the current rowset.
template<class T >
T	nanodbc::result::get (short column) const
	Gets data from the given column of the current rowset.
template<class T >
T	nanodbc::result::get (short column, T const &fallback) const
	Gets data from the given column of the current rowset.
template<class T >
T	nanodbc::result::get (string const &column_name) const
	Gets data from the given column by name of the current rowset.
template<class T >
T	nanodbc::result::get (string const &column_name, T const &fallback) const
	Gets data from the given column by name of the current rowset.

Detailed Description

Reads values from columns of the current rowset.

Attention

When nanodbc is compiled as a library, get() and get_ref() are only available for the types they are explicitly instantiated for in nanodbc.cpp. Using any other type compiles, because the declaration is visible here, but fails to link. The supported types are: bool, signed char, unsigned char, short, unsigned short, int, unsigned int, long int, unsigned long int, long long int, unsigned long long int, float, double, std::string, wide_string, std::string::value_type, wide_string::value_type, date, time, timestamp, timestampoffset and std::vector<std::uint8_t> for binary data. Each is also available wrapped in std::optional where the standard library provides it, and _variant_t on MSVC.

Function Documentation

get_ref() [1/4]

template<class T >

void nanodbc::result::get_ref	(	short	column,
		T &	result
	)		const

Gets data from the given column of the current rowset.

Columns are numbered from left to right and 0-indexed.

Parameters

column	position.
result	The column's value will be written to this parameter.

Exceptions

database_error
index_range_error
type_incompatible_error
null_access_error

get_ref() [2/4]

template<class T >

void nanodbc::result::get_ref	(	short	column,
		T const &	fallback,
		T &	result
	)		const

Gets data from the given column of the current rowset.

If the data is null, fallback is returned instead.

Columns are numbered from left to right and 0-indexed.

Parameters

column	position.
fallback	if value is null, return fallback instead.
result	The column's value will be written to this parameter.

Exceptions

database_error
index_range_error
type_incompatible_error

get_ref() [3/4]

template<class T >

void nanodbc::result::get_ref	(	string const &	column_name,
		T &	result
	)		const

Gets data from the given column by name of the current rowset.

Parameters

column_name	column's name.
result	The column's value will be written to this parameter.

Exceptions

database_error
index_range_error
type_incompatible_error
null_access_error

get_ref() [4/4]

template<class T >

void nanodbc::result::get_ref	(	string const &	column_name,
		T const &	fallback,
		T &	result
	)		const

Gets data from the given column by name of the current rowset.

If the data is null, fallback is returned instead.

Parameters

column_name	column's name.
fallback	if value is null, return fallback instead.
result	The column's value will be written to this parameter.

Exceptions

database_error
index_range_error
type_incompatible_error

get() [1/4]

template<class T >

T nanodbc::result::get

(

short

column

)

const

Gets data from the given column of the current rowset.

Columns are numbered from left to right and 0-indexed.

Parameters

column

position.

Exceptions

database_error
index_range_error
type_incompatible_error
null_access_error

get() [2/4]

template<class T >

T nanodbc::result::get	(	short	column,
		T const &	fallback
	)		const

Gets data from the given column of the current rowset.

If the data is null, fallback is returned instead.

Columns are numbered from left to right and 0-indexed.

Parameters

column	position.
fallback	if value is null, return fallback instead.

Exceptions

database_error
index_range_error
type_incompatible_error

get() [3/4]

template<class T >

T nanodbc::result::get

(

string const &

column_name

)

const

Gets data from the given column by name of the current rowset.

Parameters

column_name

column's name.

Exceptions

database_error
index_range_error
type_incompatible_error
null_access_error

get() [4/4]

template<class T >

T nanodbc::result::get	(	string const &	column_name,
		T const &	fallback
	)		const

Gets data from the given column by name of the current rowset.

If the data is null, fallback is returned instead.

Parameters

column_name	column's name.
fallback	if value is null, return fallback instead.

Exceptions

database_error
index_range_error
type_incompatible_error