RAII wrapper for PostgreSQL Result sets. More...

#include <pgsql_connection.h>

Inheritance diagram for isc::db::PgSqlResult:

Public Member Functions
	PgSqlResult (PGresult *result)
	Constructor. More...

	~PgSqlResult ()
	Destructor. More...

void	colCheck (int col) const
	Determines if a column index is valid. More...

int	getCols () const
	Returns the number of columns in the result set. More...

std::string	getColumnLabel (const int col) const
	Fetches the name of the column in a result set. More...

int	getRows () const
	Returns the number of rows in the result set. More...

	operator bool () const
	Boolean Operator. More...

	operator PGresult * () const
	Conversion Operator. More...

void	rowCheck (int row) const
	Determines if a row index is valid. More...

void	rowColCheck (int row, int col) const
	Determines if both a row and column index are valid. More...

Detailed Description

RAII wrapper for PostgreSQL Result sets.

When a Postgresql statement is executed, the results are returned in pointer allocated structure, PGresult*. Data and status information are accessed via calls to functions such as PQgetvalue() which require the results pointer. In order to ensure this structure is freed, any invocation of Psql function which returns a PGresult* (e.g. PQexec and class. Examples: {{{ PgSqlResult r(PQexec(conn_, "ROLLBACK")); }}}

This eliminates the need for an explicit release via, PQclear() and guarantees that the resources are released even if the an exception is thrown.

Definition at line 86 of file pgsql_connection.h.

Constructor & Destructor Documentation

isc::db::PgSqlResult::PgSqlResult ( PGresult * result )

Constructor.

Store the pointer to the result set to being fetched. Set row and column counts for convenience.

Parameters

result - pointer to the Postgresql client layer result If the value of is NULL, row and col values will be set to -1. This allows PgSqlResult to be passed into statement error checking.

Definition at line 43 of file pgsql_connection.cc.

isc::db::PgSqlResult::~PgSqlResult ( )

Destructor.

Frees the result set

Definition at line 66 of file pgsql_connection.cc.

Member Function Documentation

void isc::db::PgSqlResult::colCheck ( int col ) const

Determines if a column index is valid.

Parameters

col	index to range check

Exceptions

DbOperationError if the column index is out of range

Definition at line 73 of file pgsql_connection.cc.

References isc_throw.

Referenced by getColumnLabel(), and rowColCheck().

int isc::db::PgSqlResult::getCols ( ) const

inline

Returns the number of columns in the result set.

Definition at line 110 of file pgsql_connection.h.

Referenced by isc::db::PgSqlExchange::dumpRow().

std::string isc::db::PgSqlResult::getColumnLabel ( const int col ) const

Fetches the name of the column in a result set.

Returns the column name of the column from the result set. If the column index is out of range it will return the string "Unknown column:<index>"

Parameters

col	index of the column name to fetch

Returns: string containing the name of the column This method is exception safe.

Definition at line 87 of file pgsql_connection.cc.

References colCheck().

Referenced by isc::db::PgSqlExchange::dumpRow(), and isc::db::PgSqlExchange::getColumnLabel().

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int isc::db::PgSqlResult::getRows ( ) const

inline

Returns the number of rows in the result set.

Definition at line 105 of file pgsql_connection.h.

Referenced by isc::dhcp::PgSqlHostDataSourceImpl::getHostCollection().

isc::db::PgSqlResult::operator bool ( ) const

inline

Boolean Operator.

Allows testing the PgSqlResult object for emptiness: "if (result)"

Definition at line 159 of file pgsql_connection.h.

isc::db::PgSqlResult::operator PGresult * ( ) const

inline

Conversion Operator.

Allows the PgSqlResult object to be passed as the result set argument to PQxxxx functions.

Definition at line 152 of file pgsql_connection.h.

void isc::db::PgSqlResult::rowCheck ( int row ) const

Determines if a row index is valid.

Parameters

row	index to range check

Exceptions

DbOperationError if the row index is out of range

Definition at line 59 of file pgsql_connection.cc.

References isc_throw.

Referenced by isc::db::PgSqlExchange::dumpRow(), and rowColCheck().

void isc::db::PgSqlResult::rowColCheck	(	int	row,
		int	col
	)		const

Determines if both a row and column index are valid.

Parameters

row	index to range check
col	index to range check

Exceptions

DbOperationError if either the row or column index is out of range

Definition at line 81 of file pgsql_connection.cc.

References colCheck(), and rowCheck().

Referenced by isc::db::PgSqlExchange::getRawColumnValue(), and isc::db::PgSqlExchange::isColumnNull().

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

Public Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation