wxSQLite3::WindowFunction Class Reference

Interface for user defined aggregate window functions. More...

#include <wxsqlite3.h>

Public Member Functions
	WindowFunction ()
	Constructor.
virtual	~WindowFunction ()
	Virtual destructor.
int	GetCount () const
	Get counter.
void	IncrementCount ()
	Increment counter.
void	DecrementCount ()
	Decrement counter.
virtual void	Aggregate (FunctionContext &ctx)=0
	Execute the aggregate of the window function.
virtual void	Finalize (FunctionContext &ctx)=0
	Prepare the result of the aggregate window function.
virtual void	CurrentValue (FunctionContext &ctx)=0
	Get current value of the aggregate window function.
virtual void	Reverse (FunctionContext &ctx)=0
	Reverse an aggregate step of the window function.

Detailed Description

Interface for user defined aggregate window functions.

Constructor & Destructor Documentation

WindowFunction()

wxSQLite3::WindowFunction::WindowFunction ( )

inline

Constructor.

~WindowFunction()

virtual wxSQLite3::WindowFunction::~WindowFunction ( )

inlinevirtual

Virtual destructor.

Member Function Documentation

Aggregate()

virtual void wxSQLite3::WindowFunction::Aggregate ( FunctionContext & ctx )

pure virtual

Execute the aggregate of the window function.

This method is invoked for each row of the result set of the query using the aggregate window function.

Parameters

ctx	function context which can be used to access arguments and result value

CurrentValue()

virtual void wxSQLite3::WindowFunction::CurrentValue ( FunctionContext & ctx )

pure virtual

Get current value of the aggregate window function.

This method is invoked to return the current value of the aggregate. Unlike Finalize, the implementation should not delete any context.

Parameters

ctx	function context which can be used to access arguments and result value

DecrementCount()

void wxSQLite3::WindowFunction::DecrementCount ( )

inline

Decrement counter.

Finalize()

virtual void wxSQLite3::WindowFunction::Finalize ( FunctionContext & ctx )

pure virtual

Prepare the result of the aggregate window function.

This method is invoked after all rows of the result set of the query using the aggregate window function have been processed. Usually the final result is calculated and returned in this method.

Parameters

ctx	function context which can be used to access arguments and result value

GetCount()

int wxSQLite3::WindowFunction::GetCount ( ) const

inline

Get counter.

IncrementCount()

void wxSQLite3::WindowFunction::IncrementCount ( )

inline

Increment counter.

Reverse()

virtual void wxSQLite3::WindowFunction::Reverse ( FunctionContext & ctx )

pure virtual

Reverse an aggregate step of the window function.

This method is invoked to remove a row from the current window. The function arguments, if any, correspond to the row being removed.

Parameters

ctx	function context which can be used to access arguments and result value

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

• wxsqlite3.h