cppdb::backend::result Class Reference

This class represents query result. More...

#include <cppdb/backend.h>

Inheritance diagram for cppdb::backend::result:

List of all members.

Public Types
enum	next_row { last_row_reached, next_row_exists, next_row_unknown }
Public Member Functions
virtual next_row	has_next ()=0
virtual bool	next ()=0
virtual bool	fetch (int col, short &v)=0
virtual bool	fetch (int col, unsigned short &v)=0
virtual bool	fetch (int col, int &v)=0
virtual bool	fetch (int col, unsigned &v)=0
virtual bool	fetch (int col, long &v)=0
virtual bool	fetch (int col, unsigned long &v)=0
virtual bool	fetch (int col, long long &v)=0
virtual bool	fetch (int col, unsigned long long &v)=0
virtual bool	fetch (int col, float &v)=0
virtual bool	fetch (int col, double &v)=0
virtual bool	fetch (int col, long double &v)=0
virtual bool	fetch (int col, std::string &v)=0
virtual bool	fetch (int col, std::ostream &v)=0
virtual bool	fetch (int col, std::tm &v)=0
virtual bool	is_null (int col)=0
virtual int	cols ()=0
virtual int	name_to_column (std::string const &)=0
virtual std::string	column_to_name (int)=0

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Detailed Description

This class represents query result.

This object is created by statement::query call, backend developer may assume that this object will stay alive as long as statement that created it exits, i.e. statement would be destroyed after result.

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Member Enumeration Documentation

enum cppdb::backend::result::next_row

The flag that defines the information about availability of the next row in result

Enumerator:

last_row_reached	No more rows exits, next() would return false.
next_row_exists	There are more rows, next() would return true.
next_row_unknown	It is unknown, next() may return either true or false.

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Member Function Documentation

virtual int cppdb::backend::result::cols

(

)

[pure virtual]

Return the number of columns in the result. Should be valid even without calling next() first time.

virtual std::string cppdb::backend::result::column_to_name

(

int

)

[pure virtual]

Return the column name for column index starting from 0. Should throw invalid_column() if the index out of range Should be able to work even without calling next() first time.

virtual bool cppdb::backend::result::fetch	(	int	col,
		short &	v
	)		[pure virtual]

Fetch an integer value for column col starting from 0.

Should throw invalid_column() col value is invalid, should throw bad_value_cast() if the underlying data can't be converted to integer or its range is not supported by the integer type.

virtual bool cppdb::backend::result::fetch	(	int	col,
		unsigned short &	v
	)		[pure virtual]

Fetch an integer value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, should throw bad_value_cast() if the underlying data can't be converted to integer or its range is not supported by the integer type.

virtual bool cppdb::backend::result::fetch	(	int	col,
		int &	v
	)		[pure virtual]

Fetch an integer value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, should throw bad_value_cast() if the underlying data can't be converted to integer or its range is not supported by the integer type.

virtual bool cppdb::backend::result::fetch	(	int	col,
		unsigned &	v
	)		[pure virtual]

Fetch an integer value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, should throw bad_value_cast() if the underlying data can't be converted to integer or its range is not supported by the integer type.

virtual bool cppdb::backend::result::fetch	(	int	col,
		long &	v
	)		[pure virtual]

Fetch an integer value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, should throw bad_value_cast() if the underlying data can't be converted to integer or its range is not supported by the integer type.

virtual bool cppdb::backend::result::fetch	(	int	col,
		unsigned long &	v
	)		[pure virtual]

Fetch an integer value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, should throw bad_value_cast() if the underlying data can't be converted to integer or its range is not supported by the integer type.

virtual bool cppdb::backend::result::fetch	(	int	col,
		long long &	v
	)		[pure virtual]

Fetch an integer value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, should throw bad_value_cast() if the underlying data can't be converted to integer or its range is not supported by the integer type.

virtual bool cppdb::backend::result::fetch	(	int	col,
		unsigned long long &	v
	)		[pure virtual]

Fetch an integer value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, should throw bad_value_cast() if the underlying data can't be converted to integer or its range is not supported by the integer type.

virtual bool cppdb::backend::result::fetch	(	int	col,
		float &	v
	)		[pure virtual]

Fetch a floating point value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, should throw bad_value_cast() if the underlying data can't be converted to floating point value.

virtual bool cppdb::backend::result::fetch	(	int	col,
		double &	v
	)		[pure virtual]

Fetch a floating point value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, should throw bad_value_cast() if the underlying data can't be converted to floating point value.

virtual bool cppdb::backend::result::fetch	(	int	col,
		long double &	v
	)		[pure virtual]

Fetch a floating point value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, should throw bad_value_cast() if the underlying data can't be converted to floating point value.

virtual bool cppdb::backend::result::fetch	(	int	col,
		std::string &	v
	)		[pure virtual]

Fetch a string value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, any data should be convertible to text value (as formatting integer, floating point value or date-time as string).

virtual bool cppdb::backend::result::fetch	(	int	col,
		std::ostream &	v
	)		[pure virtual]

Fetch a BLOB value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid, any data should be convertible to BLOB value as text (as formatting integer, floating point value or date-time as string).

virtual bool cppdb::backend::result::fetch	(	int	col,
		std::tm &	v
	)		[pure virtual]

Fetch a date-time value for column col starting from 0. Returns true if ok, returns false if the column value is NULL and the referenced object should remain unchanged

Should throw invalid_column() col value is invalid. If the data can't be converted to date-time it should throw bad_value_cast()

virtual next_row cppdb::backend::result::has_next

(

)

[pure virtual]

Check if the next row in the result exists. If the DB engine can't perform this check without loosing data for current row, it should return next_row_unknown.

virtual bool cppdb::backend::result::is_null

(

int

col

)

[pure virtual]

Check if the column col is NULL starting from 0, should throw invalid_column() if the index out of range

virtual int cppdb::backend::result::name_to_column

(

std::string const &

)

[pure virtual]

Return the number of columns by its name. Return -1 if the name is invalid Should be able to work even without calling next() first time.

virtual bool cppdb::backend::result::next

(

)

[pure virtual]

Move to next row. Should be called before first access to any of members. If no rows remain return false, otherwise return true

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

• cppdb/backend.h