Provides an editable data model for a single database table, with foreign key support. More...

Inheritance diagram for QSqlRelationalTableModel:

Public Types
enum	JoinMode

Public Types inherited from QSqlTableModel
enum	EditStrategy

Public Slots
void	revertRow (int row)

Public Slots inherited from QSqlTableModel
void	revert ()

void	revertAll ()

virtual bool	select ()

bool	submit ()

bool	submitAll ()

Public Slots inherited from QAbstractItemModel
virtual void	revert ()

virtual bool	submit ()

Public Slots inherited from QObject
void	deleteLater ()

Public Methods
	QSqlRelationalTableModel (QObject *parent=nullptr, QSqlDatabase db=QSqlDatabase ())

virtual	~QSqlRelationalTableModel ()

void	clear () override

QVariant	data (const QModelIndex &index, int role=Qt::DisplayRole) const override

QSqlRelation	relation (int column) const

virtual QSqlTableModel *	relationModel (int column) const

bool	removeColumns (int column, int count, const QModelIndex &parent=QModelIndex ()) override

bool	select () override

bool	setData (const QModelIndex &index, const QVariant &value, int role=Qt::EditRole) override

void	setJoinMode (QSqlRelationalTableModel::JoinMode joinMode)

virtual void	setRelation (int column, const QSqlRelation &relation)

void	setTable (const QString &tableName) override

Public Methods inherited from QSqlTableModel
	QSqlTableModel (QObject *parent=nullptr, QSqlDatabase db=QSqlDatabase ())

virtual	~QSqlTableModel ()

void	clear () override

QVariant	data (const QModelIndex &index, int role=Qt::DisplayRole) const override

QSqlDatabase	database () const

EditStrategy	editStrategy () const

int	fieldIndex (const QString &fieldName) const

QString	filter () const

Qt::ItemFlags	flags (const QModelIndex &index) const override

QVariant	headerData (int section, Qt::Orientation orientation, int role=Qt::DisplayRole) const override

bool	insertRecord (int row, const QSqlRecord &record)

bool	insertRows (int row, int count, const QModelIndex &parent=QModelIndex ()) override

bool	isDirty (const QModelIndex &index) const

QSqlIndex	primaryKey () const

bool	removeColumns (int column, int count, const QModelIndex &parent=QModelIndex ()) override

bool	removeRows (int row, int count, const QModelIndex &parent=QModelIndex ()) override

virtual void	revertRow (int row)

int	rowCount (const QModelIndex &parent=QModelIndex ()) const override

bool	setData (const QModelIndex &index, const QVariant &value, int role=Qt::EditRole) override

virtual void	setEditStrategy (EditStrategy strategy)

virtual void	setFilter (const QString &filter)

bool	setRecord (int row, const QSqlRecord &record)

virtual void	setSort (int column, Qt::SortOrder order)

void	sort (int column, Qt::SortOrder order) override

QString	tableName () const

Public Methods inherited from QSqlQueryModel
	QSqlQueryModel (QObject *parent=nullptr)

virtual	~QSqlQueryModel ()

bool	canFetchMore (const QModelIndex &parent=QModelIndex ()) const override

int	columnCount (const QModelIndex &index=QModelIndex ()) const override

void	fetchMore (const QModelIndex &parent=QModelIndex ()) override

bool	insertColumns (int column, int count, const QModelIndex &parent=QModelIndex ()) override

QSqlError	lastError () const

QSqlQuery	query () const

QSqlRecord	record () const

QSqlRecord	record (int row) const

bool	setHeaderData (int section, Qt::Orientation orientation, const QVariant &value, int role=Qt::EditRole) override

void	setQuery (const QSqlQuery &query)

void	setQuery (const QString &query, const QSqlDatabase &db=QSqlDatabase ())

Public Methods inherited from QAbstractTableModel
	QAbstractTableModel (QObject *parent=nullptr)

	~QAbstractTableModel ()

bool	dropMimeData (const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) override

QModelIndex	index (int row, int column, const QModelIndex &parent=QModelIndex ()) const override

QObject *	parent () const

QModelIndex	sibling (int row, int column, const QModelIndex &index) const override

Public Methods inherited from QAbstractItemModel
	QAbstractItemModel (QObject *parent=nullptr)

virtual	~QAbstractItemModel ()

virtual QModelIndex	buddy (const QModelIndex &index) const

virtual bool	canDropMimeData (const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) const

bool	hasIndex (int row, int column, const QModelIndex &parent=QModelIndex ()) const

bool	insertColumn (int column, const QModelIndex &parent=QModelIndex ())

bool	insertRow (int row, const QModelIndex &parent=QModelIndex ())

virtual QMap< int, QVariant >	itemData (const QModelIndex &index) const

virtual QModelIndexList	match (const QModelIndex &start, int role, const QVariant &value, int hits=1, Qt::MatchFlags flags=Qt::MatchFlags (Qt::MatchStartsWith\|Qt::MatchWrap)) const

virtual QMimeData *	mimeData (const QModelIndexList &indexes) const

virtual QStringList	mimeTypes () const

bool	moveColumn (const QModelIndex &sourceParent, int sourceColumn, const QModelIndex &destinationParent, int destinationChild)

virtual bool	moveColumns (const QModelIndex &sourceParent, int sourceColumn, int count, const QModelIndex &destinationParent, int destinationChild)

bool	moveRow (const QModelIndex &sourceParent, int sourceRow, const QModelIndex &destinationParent, int destinationChild)

virtual bool	moveRows (const QModelIndex &sourceParent, int sourceRow, int count, const QModelIndex &destinationParent, int destinationChild)

QObject *	parent () const

bool	removeColumn (int column, const QModelIndex &parent=QModelIndex ())

bool	removeRow (int row, const QModelIndex &parent=QModelIndex ())

virtual QMultiHash< int, QString >	roleNames () const

virtual bool	setItemData (const QModelIndex &index, const QMap< int, QVariant > &roles)

virtual QSize	span (const QModelIndex &index) const

virtual Qt::DropActions	supportedDragActions () const

virtual Qt::DropActions	supportedDropActions () const

Public Methods inherited from QObject
	QObject (QObject *parent=nullptr)

	~QObject ()

bool	blockSignals (bool block)

const QList< QObject * > &	children () const

bool	connect (const QObject *sender, const QString &signalMethod, const QString &location, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

bool	connect (const QObject *sender, const QString &signalMethod, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

bool	disconnect (const QObject *receiver, const QString &slotMethod=QString ()) const

bool	disconnect (const QString &signalMethod, const QString &location, const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const

bool	disconnect (const QString &signalMethod=QString (), const QObject *receiver=nullptr, const QString &slotMethod=QString ()) const

void	dumpObjectInfo ()

void	dumpObjectTree ()

QList< QString >	dynamicPropertyNames () const

virtual bool	event (QEvent *event)

virtual bool	eventFilter (QObject watched, QEvent event)

template<typename T >
T	findChild (const QString &childName=QString ()) const

template<class T >
QList< T >	findChildren (const QRegularExpression &regExp, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<class T >
QList< T >	findChildren (const QString &childName=QString (), Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

bool	inherits (const QString &className) const

void	installEventFilter (QObject *filterObj)

bool	isWidgetType () const

bool	isWindowType () const

void	killTimer (int id)

const QMetaObject *	metaObject () const

void	moveToThread (QThread *targetThread)

QString	objectName () const

QObject *	parent () const

template<class T = QVariant>
T	property (const QString &name) const

void	removeEventFilter (QObject *obj)

void	setObjectName (const QString &name)

void	setParent (QObject *parent)

bool	setProperty (const QString &name, const QVariant &value)

bool	signalsBlocked () const

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)

QThread *	thread () const

Protected Methods
bool	insertRowIntoTable (const QSqlRecord &values) override

QString	orderByClause () const override

QString	selectStatement () const override

bool	updateRowInTable (int row, const QSqlRecord &values) override

Protected Methods inherited from QSqlTableModel
virtual bool	deleteRowFromTable (int row)

QModelIndex	indexInQuery (const QModelIndex &item) const override

void	setPrimaryKey (const QSqlIndex &key)

void	setQuery (const QSqlQuery &query)

Protected Methods inherited from QSqlQueryModel
virtual void	queryChange ()

void	setLastError (const QSqlError &error)

Protected Methods inherited from QAbstractItemModel
void	beginInsertColumns (const QModelIndex &parent, int first, int last)

void	beginInsertRows (const QModelIndex &parent, int first, int last)

bool	beginMoveColumns (const QModelIndex &sourceParent, int sourceFirst, int sourceLast, const QModelIndex &destinationParent, int destinationColumn)

bool	beginMoveRows (const QModelIndex &sourceParent, int sourceFirst, int sourceLast, const QModelIndex &destinationParent, int destinationRow)

void	beginRemoveColumns (const QModelIndex &parent, int first, int last)

void	beginRemoveRows (const QModelIndex &parent, int first, int last)

void	beginResetModel ()

void	changePersistentIndex (const QModelIndex &from, const QModelIndex &to)

void	changePersistentIndexList (const QModelIndexList &from, const QModelIndexList &to)

QModelIndex	createIndex (int row, int column, quintptr id) const

QModelIndex	createIndex (int row, int column, void *data=nullptr) const

void	endInsertColumns ()

void	endInsertRows ()

void	endMoveColumns ()

void	endMoveRows ()

void	endRemoveColumns ()

void	endRemoveRows ()

void	endResetModel ()

QModelIndexList	persistentIndexList () const

Protected Methods inherited from QObject
virtual void	childEvent (QChildEvent *event)

virtual void	connectNotify (const QMetaMethod &signalMethod) const

virtual void	customEvent (QEvent *event)

virtual void	disconnectNotify (const QMetaMethod &signalMethod) const

bool	isSignalConnected (const QMetaMethod &signalMethod) const

int	receivers (const QString &signal) const

QObject *	sender () const

int	senderSignalIndex () const

virtual void	timerEvent (QTimerEvent *event)

Additional Inherited Members
Public Signals inherited from QSqlTableModel
void	beforeDelete (int row)

void	beforeInsert (QSqlRecord &record)

void	beforeUpdate (int row, QSqlRecord &record)

void	primeInsert (int row, QSqlRecord &record)

Public Signals inherited from QAbstractItemModel
void	columnsAboutToBeInserted (const QModelIndex &parent, int first, int last)

void	columnsAboutToBeMoved (const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationColumn)

void	columnsAboutToBeRemoved (const QModelIndex &parent, int first, int last)

void	columnsInserted (const QModelIndex &parent, int first, int last)

void	columnsMoved (const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationColumn)

void	columnsRemoved (const QModelIndex &parent, int first, int last)

void	dataChanged (const QModelIndex &topLeft, const QModelIndex &bottomRight, const QVector< int > &roles=QVector< int >())

void	headerDataChanged (Qt::Orientation orientation, int first, int last)

void	layoutAboutToBeChanged (const QList< QPersistentModelIndex > &parents=QList< QPersistentModelIndex >(), QAbstractItemModel::LayoutChangeHint hint=QAbstractItemModel::NoLayoutChangeHint)

void	layoutChanged (const QList< QPersistentModelIndex > &parents=QList< QPersistentModelIndex >(), QAbstractItemModel::LayoutChangeHint hint=QAbstractItemModel::NoLayoutChangeHint)

void	modelAboutToBeReset ()

void	modelReset ()

void	rowsAboutToBeInserted (const QModelIndex &parent, int first, int last)

void	rowsAboutToBeMoved (const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationRow)

void	rowsAboutToBeRemoved (const QModelIndex &parent, int first, int last)

void	rowsInserted (const QModelIndex &parent, int first, int last)

void	rowsMoved (const QModelIndex &sourceParent, int sourceStart, int sourceEnd, const QModelIndex &destinationParent, int destinationRow)

void	rowsRemoved (const QModelIndex &parent, int first, int last)

Public Signals inherited from QObject
void	destroyed (QObject *obj=nullptr)

void	objectNameChanged (const QString &objectName)

Static Public Methods inherited from QObject
static bool	connect (const QObject sender, const QMetaMethod &signalMethod, const QObject receiver, const QMetaMethod &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

static bool	connect (const QObject sender, const QString &signalMethod, const QObject receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection, const QString &location=QString ())

static bool	connect (const QObject sender, const QString &signalMethod, const QString &location, const QObject receiver, const QString &slotMethod, Qt::ConnectionType type=Qt::AutoConnection)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool	connect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver receiver, SlotReturn (SlotClass::slotMethod)(SlotArgs...), Qt::ConnectionType type=Qt::AutoConnection)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool	connect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, T slotLambda, Qt::ConnectionType type=Qt::AutoConnection)

static bool	disconnect (const QObject sender, const QMetaMethod &signalMethod, const QObject receiver, const QMetaMethod &slotMethod)

static bool	disconnect (const QObject sender, const QString &signalMethod, const QObject receiver, const QString &slotMethod)

static bool	disconnect (const QObject sender, const QString &signalMethod, const QString &location, const QObject receiver, const QString &slotMethod)

static bool	disconnect (const QObject sender, std::nullptr_t, const QObject receiver, std::nullptr_t)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class SlotClass , class... SlotArgs, class SlotReturn >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver receiver, SlotReturn (SlotClass::slotMethod)(SlotArgs...))

template<class Sender , class SignalClass , class... SignalArgs, class Receiver >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, std::nullptr_t slotMethod=nullptr)

template<class Sender , class SignalClass , class... SignalArgs, class Receiver , class T >
static bool	disconnect (const Sender sender, void (SignalClass::signalMethod)(SignalArgs...), const Receiver *receiver, T slotMethod)

static QMetaObject &	staticMetaObject ()

static QString	tr (const char text, const char comment=nullptr, std::optional< int > numArg=std::optional< int >())

Protected Slots inherited from QAbstractItemModel
void	resetInternalData ()

Properties inherited from QObject
	objectName

Related Functions inherited from QObject
T	qobject_cast (QObject *object)

	QObjectList

Detailed Description

The QSqlRelationalTableModel class provides an editable data model for a single database table, with foreign key support. QSqlRelationalTableModel acts like QSqlTableModel, but allows columns to be set as foreign keys into other database tables.

The screenshot on the left shows a plain QSqlTableModel in a QTableView. Foreign keys (city and country) are not resolved to human-readable values. The screenshot on the right shows a QSqlRelationalTableModel, with foreign keys resolved into human-readable text strings.

The following code shows how the QSqlRelationalTableModel was configured.

model->setTable("employee");
 
model->setRelation(2, QSqlRelation("city", "id", "name"));
model->setRelation(3, QSqlRelation("country", "id", "name"));

The setRelation() function calls establish a relationship between two tables. The first call specifies that column 2 in table employee is a foreign key that maps with field id of table city, and that the view should present the city's name field to the user. The second call does something similar with column 3.

If you use a read-write QSqlRelationalTableModel, you probably want to use QSqlRelationalDelegate on the view. Unlike the default delegate, QSqlRelationalDelegate provides a combobox for fields that are foreign keys into other tables. To use the class, simply call QAbstractItemView::setItemDelegate() on the view with an instance of QSqlRelationalDelegate:

QTableView *view = new QTableView;
view->setModel(model);
view->setItemDelegate(new QSqlRelationalDelegate(view));

Notes:

The table must have a primary key declared.
The table's primary key may not contain a relation to another table.
If a relational table contains keys that refer to non-existent rows in the referenced table, the rows containing the invalid keys will not be exposed through the model. The user or the database is responsible for keeping referential integrity.
If a relation's display column name is also used as a column name in the main table, or if it is used as display column name in more than one relation it will be aliased. The alias is the relation's table name and display column name joined by an underscore (e.g. tablename_columnname). All occurrences of the duplicate display column name are aliased when duplication is detected, but no aliasing is done to the column names in the main table. The aliasing does not affect QSqlRelation, so QSqlRelation::displayColumn() will return the original display column name, but QSqlRecord::fieldName() will return aliases.
When using setData() the role should always be Qt::EditRole and when using data() the role should always be Qt::DisplayRole.

See also: QSqlRelation, QSqlRelationalDelegate

Member Enumeration Documentation

enum QSqlRelationalTableModel::JoinMode

This enum specifies the type of mode to use when joining two tables.

Constant	Value	Description
`QSqlRelationalTableModel::InnerJoin`	`0`	Inner join mode, return rows when there is at least one match in both tables.
`QSqlRelationalTableModel::LeftJoin`	`1`	Left join mode, returns all rows from the left table (table_name1), even if there are no matches in the right table (table_name2).

See also: QSqlRelationalTableModel::setJoinMode()

Constructor & Destructor Documentation

QSqlRelationalTableModel::QSqlRelationalTableModel	(	QObject *	parent = `nullptr`,
		QSqlDatabase	db = `QSqlDatabase()`
	)

explicit

Creates an empty QSqlRelationalTableModel and sets the parent to parent and the database connection to db. If db is not valid, the default database connection will be used.

QSqlRelationalTableModel::~QSqlRelationalTableModel ( )

virtual

Destroys the object and frees any allocated resources.

Method Documentation

void QSqlRelationalTableModel::clear ( )

overridevirtual

Reimplemented from QSqlQueryModel::clear()

QVariant QSqlRelationalTableModel::data	(	const QModelIndex &	index,
		int	role = `Qt::DisplayRole`
	)		const

overridevirtual

See also: setData()

Reimplemented from QSqlQueryModel::data()

bool QSqlRelationalTableModel::insertRowIntoTable ( const QSqlRecord & values )

overrideprotectedvirtual

Reimplemented from QSqlTableModel::insertRowIntoTable()

QString QSqlRelationalTableModel::orderByClause ( ) const

overrideprotectedvirtual

Reimplemented from QSqlTableModel::orderByClause()

QSqlRelation QSqlRelationalTableModel::relation ( int column ) const

Returns the relation for the column, or an invalid relation if no relation is set.

See also: setRelation(), QSqlRelation::isValid()

QSqlTableModel * QSqlRelationalTableModel::relationModel ( int column ) const

virtual

Returns a QSqlTableModel object for accessing the table for which column is a foreign key or a nullptr if there is no relation for the given column. The returned object is owned by the QSqlRelationalTableModel.

See also: setRelation(), relation()

bool QSqlRelationalTableModel::removeColumns	(	int	column,
		int	count,
		const QModelIndex &	parent = `QModelIndex()`
	)

overridevirtual

Reimplemented from QSqlQueryModel::removeColumns()

void QSqlRelationalTableModel::revertRow ( int row )

slot

Reimplemented from QSqlTableModel::revertRow()

bool QSqlRelationalTableModel::select ( )

override

Reimplemented from QSqlTableModel::select()

QString QSqlRelationalTableModel::selectStatement ( ) const

overrideprotectedvirtual

Reimplemented from QSqlTableModel::selectStatement()

bool QSqlRelationalTableModel::setData	(	const QModelIndex &	index,
		const QVariant &	value,
		int	role = `Qt::EditRole`
	)

overridevirtual

Sets the data for the role in the item with the specified index to the value given. Depending on the edit strategy, the value might be applied to the database at once, or it may be cached in the model. Returns true if the value could be set, or false on error (for example, if index is out of bounds). For relational columns, value must be the index, not the display value. The index must also exist in the referenced table, otherwise the methods returns false.

See also: editStrategy(), data(), submit(), revertRow()

Reimplemented from QAbstractItemModel::setData()

void QSqlRelationalTableModel::setJoinMode ( QSqlRelationalTableModel::JoinMode joinMode )

Sets the SQL join mode to the value given by joinMode to show or hide rows with NULL foreign keys. In InnerJoin mode (the default) these rows will not be shown; use the LeftJoin mode if you want to show them.

See also: QSqlRelationalTableModel::JoinMode

void QSqlRelationalTableModel::setRelation	(	int	column,
		const QSqlRelation &	relation
	)

virtual

Allows the specified column to be a foreign index specified by relation. The table's primary key may not contain a relation to another table.

The setRelation() call in the following example specifies that column 2 in table employee is a foreign key that maps with field id of table city, and that the view should present the city's name field to the user.

model->setTable("employee");

model->setRelation(2, QSqlRelation("city", "id", "name"));

See also: relation()

void QSqlRelationalTableModel::setTable ( const QString & tableName )

overridevirtual

Reimplemented from QSqlTableModel::setTable()

bool QSqlRelationalTableModel::updateRowInTable	(	int	row,
		const QSqlRecord &	values
	)

overrideprotectedvirtual

Reimplemented from QSqlTableModel::updateRowInTable()

Public Types

Public Slots

Public Methods

Protected Methods

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Method Documentation