mysqlpp::UseQueryResult Class Reference

StoreQueryResult set type for "use" queries. More...

#include <result.h>

Inheritance diagram for mysqlpp::UseQueryResult:

Collaboration diagram for mysqlpp::UseQueryResult:

Public Member Functions
	UseQueryResult ()
	Default constructor.
	UseQueryResult (MYSQL_RES *result, DBDriver *dbd, bool te=true)
	Create the object, fully initialized.
	UseQueryResult (const UseQueryResult &other)
	Create a copy of another UseQueryResult object.
	~UseQueryResult ()
	Destroy object.
UseQueryResult &	operator= (const UseQueryResult &rhs)
	Copy another UseQueryResult object's data into this object.
const Field &	fetch_field () const
	Returns the next field in this result set.
const Field &	fetch_field (Fields::size_type i) const
	Returns the given field in this result set.
const unsigned long *	fetch_lengths () const
	Returns the lengths of the fields in the current row of the result set.
Row	fetch_row () const
	Returns the next row in a "use" query's result set. More...
MYSQL_ROW	fetch_raw_row () const
	Wraps mysql_fetch_row() in MySQL C API.
void	field_seek (Fields::size_type field) const
	Jumps to the given field within the result set. More...
	operator MYSQL_RES * () const
	Return the pointer to the underlying MySQL C API result set object. More...
Public Member Functions inherited from mysqlpp::ResultBase
virtual	~ResultBase ()
	Destroy object.
const Field &	fetch_field () const
	Returns the next field in this result set.
const Field &	fetch_field (Fields::size_type i) const
	Returns the given field in this result set.
const Field &	field (unsigned int i) const
	Get the underlying Field structure given its index.
const Fields &	fields () const
	Get the underlying Fields structure.
const std::string &	field_name (int i) const
	Get the name of the field at the given index.
const RefCountedPointer< FieldNames > &	field_names () const
	Get the names of the fields within this result set.
int	field_num (const std::string &) const
	Get the index of the named field. More...
const FieldTypes::value_type &	field_type (int i) const
	Get the type of a particular field within this result set.
const RefCountedPointer< FieldTypes > &	field_types () const
	Get a list of the types of the fields within this result set.
size_t	num_fields () const
	Returns the number of fields in this result set.
const char *	table () const
	Return the name of the table the result set comes from.
Public Member Functions inherited from mysqlpp::OptionalExceptions
	OptionalExceptions (bool e=true)
	Default constructor. More...
virtual	~OptionalExceptions ()
	Destroy object.
void	enable_exceptions () const
	Enable exceptions from the object.
void	disable_exceptions () const
	Disable exceptions from the object.
bool	throw_exceptions () const
	Returns true if exceptions are enabled.

Additional Inherited Members
Protected Member Functions inherited from mysqlpp::ResultBase
	ResultBase ()
	Create empty object.
	ResultBase (MYSQL_RES *result, DBDriver *dbd, bool te=true)
	Create the object, fully initialized.
	ResultBase (const ResultBase &other)
	Create object as a copy of another ResultBase.
ResultBase &	copy (const ResultBase &other)
	Copy another ResultBase object's contents into this one.
Protected Member Functions inherited from mysqlpp::OptionalExceptions
void	set_exceptions (bool e) const
	Sets the exception state to a particular value. More...
Protected Attributes inherited from mysqlpp::ResultBase
DBDriver *	driver_
	Access to DB driver; fully initted if nonzero.
Fields	fields_
	list of fields in result
RefCountedPointer< FieldNames >	names_
	list of field names in result
RefCountedPointer< FieldTypes >	types_
	list of field types in result
Fields::size_type	current_field_
	Default field index used by fetch_field() More...

Detailed Description

StoreQueryResult set type for "use" queries.

See the user manual for the reason you might want to use this even though its interface is less friendly than StoreQueryResult's.

Member Function Documentation

fetch_row()

Row mysqlpp::UseQueryResult::fetch_row

(

)

const

Returns the next row in a "use" query's result set.

This is a thick wrapper around DBDriver::fetch_row(). It does a lot of error checking before returning the Row object containing the row data.

See also

fetch_raw_row()

References mysqlpp::ResultBase::driver_, mysqlpp::DBDriver::errnum(), mysqlpp::DBDriver::error(), fetch_lengths(), mysqlpp::DBDriver::fetch_row(), mysqlpp::RefCountedPointer< T, Destroyer >::raw(), and mysqlpp::OptionalExceptions::throw_exceptions().

Referenced by mysqlpp::Query::for_each(), and mysqlpp::Query::store_if().

field_seek()

void mysqlpp::UseQueryResult::field_seek ( Fields::size_type  field ) const

inline

Jumps to the given field within the result set.

Calling this allows you to reset the default field index used by fetch_field().

operator MYSQL_RES *()

mysqlpp::UseQueryResult::operator MYSQL_RES * ( ) const

inline

Return the pointer to the underlying MySQL C API result set object.

While this has obvious inherent value for those times you need to dig beneath the MySQL++ interface, it has subtler value. It effectively stands in for operator bool(), operator !(), operator ==(), and operator !=(), because the C++ compiler can implement all of these with a MYSQL_RES*.

Of these uses, the most valuable is using the UseQueryResult object in bool context to determine if the query that created

Query q("....");
if (UseQueryResult res = q.use()) {
    // Can use 'res', query succeeded
}
else {
    // Query failed, call Query::error() or ::errnum() for why
}

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

• result.h
• result.cpp