#include <dataset.h>

Detailed Description

A dataset is an efficient in-memory-cache for rlational database data.

It is optimized for read/modify/write operations. Usually you tell the dataset object what you want from the database, modify the queried data, and write the queried data back. Datasets can also be used to write new data into the database.

Configuring the dataset:

Add table objects which contain the columns you're interested in. Add an optional Filter object which basically describes a WHERE statement.

Once the dataset has been configured you can fill the dataset with data by either doing a PerformQuery() (which creates a new result ValueTable), or by filling out the ValueTable by hand.

To write modified data in the ValueTable back to the database, invoke the CommitChanges() method. This will try to figure out the most efficient way to write the modified data back into the database.

Copyright: (C) 2006 Radon Labs GmbH (C) 2013-2016 Individual contributors, see AUTHORS file

Inherits Core::RefCounted.

Inherited by Db::Sqlite3Dataset.

Public Member Functions
	Dataset ()
	constructor

virtual	~Dataset ()
	destructor

void	AddColumn (const Attr::AttrId &attrId)
	add the columns you're interested in

void	AddAllTableColumns ()
	add all the table columns to the dataset

const Ptr< Table > &	GetTable () const
	get pointer to database table this set is associated with

const Ptr< FilterSet > &	Filter ()
	access to query filter

const Ptr< ValueTable > &	Values ()
	access to value table

virtual void	PerformQuery (bool appendResult=false)
	fill value table from database

virtual void	CommitChanges (bool newRowsAsUpdate=false)
	commit modified values to the database

virtual void	CommitDeletedRows ()
	commit deleted rows only to the database

Public Member Functions inherited from Core::RefCounted
	RefCounted ()
	constructor

int	GetRefCount () const
	get the current refcount

void	AddRef ()
	increment refcount by one

void	Release ()
	decrement refcount and destroy object if refcount is zero

bool	IsInstanceOf (const Rtti &rtti) const
	return true if this object is instance of given class

bool	IsInstanceOf (const Util::String &className) const
	return true if this object is instance of given class by string

bool	IsInstanceOf (const Util::FourCC &classFourCC) const
	return true if this object is instance of given class by fourcc

bool	IsA (const Rtti &rtti) const
	return true if this object is instance of given class, or a derived class

bool	IsA (const Util::String &rttiName) const
	return true if this object is instance of given class, or a derived class, by string

bool	IsA (const Util::FourCC &rttiFourCC) const
	return true if this object is instance of given class, or a derived class, by fourcc

const Util::String &	GetClassName () const
	get the class name

Util::FourCC	GetClassFourCC () const
	get the class FourCC code

Protected Member Functions
void	SetTable (const Ptr< Table > &t)
	set pointer to database table

virtual bool	Connect ()
	connect to database table

virtual void	Disconnect ()
	disconnect from database table

bool	IsConnected () const
	return true if the dataset is connected

Protected Member Functions inherited from Core::RefCounted
virtual	~RefCounted ()
	destructor (called when refcount reaches zero)

Protected Attributes
bool	isConnected

Ptr< Table >	table

Ptr< FilterSet >	filter

Ptr< ValueTable >	values

Private Member Functions
	__DeclareClass (Dataset)

Friends
class	Table

Additional Inherited Members
Static Public Member Functions inherited from Core::RefCounted
static void	DumpRefCountingLeaks ()
	dump refcounting leaks, call at end of application (NEBULA_DEBUG builds only!)

Constructor & Destructor Documentation

◆ Dataset()

Db::Dataset::Dataset ( )

constructor

◆ ~Dataset()

Db::Dataset::~Dataset ( )

virtual

destructor

Member Function Documentation

◆ __DeclareClass()

Db::Dataset::__DeclareClass ( Dataset )

private

◆ AddAllTableColumns()

void Db::Dataset::AddAllTableColumns ( )

add all the table columns to the dataset

◆ AddColumn()

void Db::Dataset::AddColumn ( const Attr::AttrId & attrId )

add the columns you're interested in

◆ CommitChanges()

void Db::Dataset::CommitChanges ( bool newRowsAsUpdate = false )

virtual

commit modified values to the database

This will write back any changes in the ValueTable back into the database.

This includes new columns, new rows and modified existing values.

NOTE: the actual functionality of this method should be implemented in a subclass.

Reimplemented in Db::Sqlite3Dataset.

◆ CommitDeletedRows()

void Db::Dataset::CommitDeletedRows ( )

virtual

commit deleted rows only to the database

This will delete all rows marked as deleted from the database.

It is sometimes necessary to perform this operation immediately.

Reimplemented in Db::Sqlite3Dataset.

◆ Connect()

bool Db::Dataset::Connect ( )

protectedvirtual

connect to database table

Connect the dataset to the table it is associated with.

A dataset will only be connected to its table during database operations.

Reimplemented in Db::Sqlite3Dataset.

◆ Disconnect()

void Db::Dataset::Disconnect ( )

protectedvirtual

disconnect from database table

Disconnect the dataset from the table it is associated with.

This will commit any changes to the value table into the database.

Reimplemented in Db::Sqlite3Dataset.

◆ Filter()

const Ptr< FilterSet > & Db::Dataset::Filter ( )

inline

access to query filter

◆ GetTable()

const Ptr< Table > & Db::Dataset::GetTable ( ) const

inline

get pointer to database table this set is associated with

◆ IsConnected()

bool Db::Dataset::IsConnected ( ) const

inlineprotected

return true if the dataset is connected

◆ PerformQuery()

void Db::Dataset::PerformQuery ( bool appendResult = false )

virtual

fill value table from database

This will create a new value table object by performing a query from the database.

The query will be built from the TableColumnPairs, Relations and the optional Filter set on this dataset object. If possible, the previous query will be re-used to save compile time. The query will completely overwrite the current value table.

NOTE: the actual functionality of this method should be implemented in a subclass.

Reimplemented in Db::Sqlite3Dataset.

◆ SetTable()

void Db::Dataset::SetTable ( const Ptr< Table > & t )

inlineprotected

set pointer to database table

◆ Values()

const Ptr< ValueTable > & Db::Dataset::Values ( )

inline

access to value table

Friends And Related Symbol Documentation

◆ Table

friend class Table

friend

Member Data Documentation

◆ filter

Ptr<FilterSet> Db::Dataset::filter

protected

◆ isConnected

bool Db::Dataset::isConnected

protected

◆ table

Ptr<Table> Db::Dataset::table

protected

◆ values

Ptr<ValueTable> Db::Dataset::values

protected

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

/github/workspace/code/addons/db/dataset.h
/github/workspace/code/addons/db/dataset.cc

Detailed Description

Public Member Functions

Protected Member Functions

Protected Attributes

Private Member Functions

Friends

Additional Inherited Members

Constructor & Destructor Documentation

◆ Dataset()

◆ ~Dataset()

Member Function Documentation

◆ __DeclareClass()

◆ AddAllTableColumns()

◆ AddColumn()

◆ CommitChanges()

◆ CommitDeletedRows()

◆ Connect()

◆ Disconnect()

◆ Filter()

◆ GetTable()

◆ IsConnected()

◆ PerformQuery()

◆ SetTable()

◆ Values()

Friends And Related Symbol Documentation

◆ Table

Member Data Documentation

◆ filter

◆ isConnected

◆ table

◆ values