Hazy_Database Class Reference

This class provides database connection, executes update and select queries. More...

#include <postgres_util.h>

List of all members.

Public Member Functions
	Hazy_Database (std::string dbname)
	Default constructor that takes only database name (needs to consider username and password, too!).
int	execute_statement_msg (const char *stmt, const char *msg)
	Executes given statement.
int	execute_query_msg_text (const char *query, const char *msg, std::string &result)
	Executes given statement and retrieve string value.
int	execute_query_msg_double (const char *query, const char *msg, double &result)
	Executes given statement and retrieve double value.
int	execute_query_msg_int (const char *query, const char *msg, int &result)
	Executes given statement and retrieve int value.
int	copy_to_table (std::istream &s, std::string &table_name, std::string &delimiter)
	Copies given content of the stream to the given table.
int	copy_from_table (std::ostream &s, std::string &table_name, std::string &delimiter)
	Copies content of the database table to the output stream.
template<class T>
int	postgresTupleParser (const char *szQuery, int(*tuple_parser)(PGresult *r, int index, T &out), std::vector< T > &_out)
	Parses the postgres tuples and stores them in a vector.
template<class K, class T>
int	postgresMapParser (const char *szQuery, int(*tuple_parser)(PGresult *r, int index, K &k, T &v), std::map< K, T > &_out)
	Parses the postgres tuples in hybrid approach and stores them in a map.
void	closeConnection ()
	Closes database connection.
Private Member Functions
void	exit_nicely ()
	When query gives error, then it closes database connection.
Private Attributes
PGconn *	conn
	Connection object.
PGresult *	res
	Result object.

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Detailed Description

This class provides database connection, executes update and select queries.

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Constructor & Destructor Documentation

Hazy_Database::Hazy_Database

(

std::string

dbname

)

Default constructor that takes only database name (needs to consider username and password, too!).

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Member Function Documentation

void Hazy_Database::closeConnection

(

)

Closes database connection.

int Hazy_Database::copy_from_table	(	std::ostream &	s,
		std::string &	table_name,
		std::string &	delimiter
	)

Copies content of the database table to the output stream.

Parameters:

[in]	s	output stream that the table content will be written to
[in]	table_name	name of the table in the database that has the data
[in]	delimiter	delimiter that will be used to format data in the output stream

Returns:

success

int Hazy_Database::copy_to_table	(	std::istream &	s,
		std::string &	table_name,
		std::string &	delimiter
	)

Copies given content of the stream to the given table.

Parameters:

[in]	s	input stream that holds data
[in]	table_name	table name in the database that data will be copied
[in]	delimiter	delimiter that used to format data in the input stream

Returns:

success

int Hazy_Database::execute_query_msg_double	(	const char *	query,
		const char *	msg,
		double &	result
	)

Executes given statement and retrieve double value.

Parameters:

[in]	query	query statement
[in]	msg	error msg to print in case of error
[out]	result	double value to be retrieved

Returns:

success

int Hazy_Database::execute_query_msg_int	(	const char *	query,
		const char *	msg,
		int &	result
	)

Executes given statement and retrieve int value.

Parameters:

[in]	query	query statement
[in]	msg	error msg to print in case of error
[out]	result	int value to be retrieved

Returns:

success

int Hazy_Database::execute_query_msg_text	(	const char *	query,
		const char *	msg,
		std::string &	result
	)

Executes given statement and retrieve string value.

Parameters:

[in]	query	query statement
[in]	msg	error msg to print in case of error
[out]	result	string value to be retrieved

Returns:

success

int Hazy_Database::execute_statement_msg	(	const char *	stmt,
		const char *	msg
	)

Executes given statement.

Parameters:

[in]	stmt	query statement
[in]	msg	error msg to print in case of error

Returns:

success

void Hazy_Database::exit_nicely

(

)

[inline, private]

When query gives error, then it closes database connection.

template<class K, class T>

int Hazy_Database::postgresMapParser	(	const char *	szQuery,
		int(*)(PGresult *r, int index, K &k, T &v)	tuple_parser,
		std::map< K, T > &	_out
	)			[inline]

Parses the postgres tuples in hybrid approach and stores them in a map.

Parameters:

[in]	szQuery	query to retrieve tuples from postgres
[in]	tuple_parser	function pointer to parse the tuples
[out]	_out	the map that parsed tuples will be stored

Returns:

success

template<class T>

int Hazy_Database::postgresTupleParser	(	const char *	szQuery,
		int(*)(PGresult *r, int index, T &out)	tuple_parser,
		std::vector< T > &	_out
	)			[inline]

Parses the postgres tuples and stores them in a vector.

Parameters:

[in]	szQuery	query to retrieve tuples from postgres
[in]	tuple_parser	function pointer to parse the tuples
[out]	_out	the vector that parsed tuples will be stored

Returns:

success

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Member Data Documentation

PGconn* Hazy_Database::conn [private]

Connection object.

PGresult* Hazy_Database::res [private]

Result object.

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

• postgres_util.h
• postgres_util.cxx

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