Dv::MySql::CommandImpl Class Reference

MySql specific implementation class for Sql::Command. More...

#include <mysqldb.h>

Inheritance diagram for Dv::MySql::CommandImpl:

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Collaboration diagram for Dv::MySql::CommandImpl:

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List of all members.

Private Member Functions
	CommandImpl (Db &db, Sql::Command &cmd)
virtual	~CommandImpl ()
	Destructor.
std::string	mysql_error_message (const std::string &msg)
	Fetch mysql errror message.
void	sync (unsigned int row) throw (std::logic_error)
	Synchronize cursor to point to row number `r`.
Db &	db ()
	Return error code.
void	exec () throw (std::runtime_error)
	Execute this command.
void	fetch (std::vector< std::string > &data, unsigned int row) throw (std::logic_error)
	Fetch row from query result.
void	fetch (std::vector< std::string > &v, std::vector< bool > &nulls, unsigned int r) throw (std::logic_error)
	Fetch r'th row of query result and set corresponding null flags.
void	fetch (std::string &data, unsigned int row, unsigned int column) throw (std::logic_error)
	Fetch c'th element in r'th row of query result.
const char *	fetch_data_ptr (unsigned int row, unsigned int column, size_t &size) throw (std::logic_error)
	Grab a pointer to column of a row in the query result.
void	escape (const std::string &s)
	Write quoted and escaped version of parameter to textstream().
void	table (Dv::Sql::Table::Ref &table) const throw (std::logic_error)
unsigned int	insertid () const
	Auto_increment insertid of last query.
Private Attributes
Db &	db_
void *	result_
int	row_
unsigned long *	lengths_
void *	mrow_
bool	ran_
Friends
class	Db

Detailed Description

MySql specific implementation class for Sql::Command.

Definition at line 226 of file mysqldb.h.

Constructor & Destructor Documentation

Dv::MySql::CommandImpl::CommandImpl	(	Db &	db,
		Sql::Command &	cmd
	)			`[private]`

virtual Dv::MySql::CommandImpl::~CommandImpl ( ) [private, virtual]

Destructor.

Virtual because it will be subclassed.

Reimplemented from Dv::Sql::CommandImpl.

Member Function Documentation

std::string Dv::MySql::CommandImpl::mysql_error_message ( const std::string & msg ) [private]

Fetch mysql errror message.

Parameters:

msg

default value

Returns:: mysql specific message or default message is none is available

void Dv::MySql::CommandImpl::sync ( unsigned int row ) throw (std::logic_error) [private]

Synchronize cursor to point to row number r.

Parameters:

row number to make cursor (mrow_ ) point to.

Exceptions:

std::logic_error

if the operation fails.

Db& Dv::MySql::CommandImpl::db ( ) [inline, private, virtual]

Return error code.

MySql::Db connection of this command.

Returns:: MySql::Db connection of this command.

Implements Dv::Sql::CommandImpl.

Definition at line 258 of file mysqldb.h.

References db_.

void Dv::MySql::CommandImpl::exec ( ) throw (std::runtime_error) [private, virtual]

Execute this command.

This function is part of the Sql::CommandImpl required interface.

Exceptions:

std::runtime_error

iff the sql command failed.

Implements Dv::Sql::CommandImpl.

void Dv::MySql::CommandImpl::fetch	(	std::vector< std::string > &	data,
		unsigned int	row
	)			throw (std::logic_error) `[private, virtual]`

Fetch row from query result.

Note that NULL values will be stored as "NULL" strings.

This function is part of the Sql::CommandImpl required interface.

Parameters:

	data	to append row data to
	row	number of row to retrieve data from

Exceptions:

std::logic_error

if row not available

Implements Dv::Sql::CommandImpl.

void Dv::MySql::CommandImpl::fetch	(	std::vector< std::string > &	v,
		std::vector< bool > &	nulls,
		unsigned int	r
	)			throw (std::logic_error) `[private, virtual]`

Fetch r'th row of query result and set corresponding null flags.

This function is part of the Sql::CommandImpl required interface.

Parameters:

	v	column values will be appended to this vector, a NULL value will be appended as an empty string
	nulls	one value (true iff the column value is NULL) for each column will be appended to this vector
	r	number of row in result to retrieve values for

Exceptions:

std::logic_error

if row not available

Implements Dv::Sql::CommandImpl.

void Dv::MySql::CommandImpl::fetch	(	std::string &	data,
		unsigned int	row,
		unsigned int	column
	)			throw (std::logic_error) `[private, virtual]`

Fetch c'th element in r'th row of query result.

This function is part of the Sql::CommandImpl required interface.

Parameters:

	data	where column value is to be stored
	row	number to retrieve
	column	number in row to retrieve

Exceptions:

std::logic_error

if row or column not available

Reimplemented from Dv::Sql::CommandImpl.

const char* Dv::MySql::CommandImpl::fetch_data_ptr	(	unsigned int	row,
		unsigned int	column,
		size_t &	size
	)			throw (std::logic_error) `[private, virtual]`

Grab a pointer to column of a row in the query result.

This low-level function avoids copying from the mysql query result. It simply returns a pointer to the start of the relevant data and sets size to the size of the data. It may be usefule to process e.g. large blobs.

 Dv::Sql::Command q(...);
 q.exec();
 for (size_t r=0; r<q.nrows(); ++r) {
   size_t size;
   const char* begin = q.fetch_data_ptr(r, 0, size);
   std::copy(begin, begin+size, std::ostream_iterator<char>(std::cout, '\n');
 }

Parameters:

	row	number of row containing the data
	column	number of the column in the row containin the data
	size	output parameter: will be set to the size of the data