QgsQueryBuilder Class Reference

Query Builder for layers. More...

#include <qgsquerybuilder.h>

Inheritance diagram for QgsQueryBuilder:

Public Slots
void	accept () override
void	clear ()
void	loadQuery ()
	Load query from the XML file.
void	reject () override
void	saveQuery ()
	Save query to the XML file.
void	setDatasourceDescription (const QString &uri)
virtual void	test ()
	The default implementation tests that the constructed sql statement to see if the vector layer data provider likes it.

Public Member Functions
	QgsQueryBuilder (QgsVectorLayer *layer, QWidget *parent=nullptr, Qt::WindowFlags fl=QgsGuiUtils::ModalDialogFlags)
	This constructor is used when the query builder is called from the vector layer properties dialog.
QgsCodeEditor *	codeEditorWidget () const
	Returns the code editor widget for the SQL.
void	setSql (const QString &sqlStatement)
	Set the sql statement to display in the dialog.
void	setSubsetString (const QString &subsetString) override
	Sets a subset string into the dialog.
void	showEvent (QShowEvent *event) override
QString	sql () const
	Returns the sql statement entered in the dialog.
QString	subsetString () const override
	Returns the subset string entered in the dialog.
Public Member Functions inherited from QgsSubsetStringEditorInterface
	QgsSubsetStringEditorInterface (QWidget *parent=nullptr, Qt::WindowFlags fl=QgsGuiUtils::ModalDialogFlags)
	Constructor.

Static Public Member Functions
static bool	loadQueryFromFile (QString &subset)
	Load query from the XML file.
static bool	saveQueryToFile (const QString &subset)
	Save query to the XML file.

Friends
class	TestQgsQueryBuilder

Detailed Description

Query Builder for layers.

The query builder allows interactive creation of a SQL for limiting the features displayed in a vector layer. The fields in the table are displayed and sample values (or all values) can be viewed to aid in constructing the query. A test function returns the number of features that will be returned.

Definition at line 45 of file qgsquerybuilder.h.

Constructor & Destructor Documentation

QgsQueryBuilder()

QgsQueryBuilder::QgsQueryBuilder	(	QgsVectorLayer *	layer,
		QWidget *	parent = nullptr,
		Qt::WindowFlags	fl = QgsGuiUtils::ModalDialogFlags
	)

This constructor is used when the query builder is called from the vector layer properties dialog.

Parameters

layer	existing vector layer
parent	Parent widget
fl	dialog flags

Definition at line 39 of file qgsquerybuilder.cpp.

Member Function Documentation

accept

void QgsQueryBuilder::accept ( )

overrideslot

Definition at line 277 of file qgsquerybuilder.cpp.

clear

void QgsQueryBuilder::clear ( )

slot

Definition at line 438 of file qgsquerybuilder.cpp.

codeEditorWidget()

QgsCodeEditor * QgsQueryBuilder::codeEditorWidget ( ) const

inline

Returns the code editor widget for the SQL.

Since

QGIS 3.18

Definition at line 92 of file qgsquerybuilder.h.

loadQuery

void QgsQueryBuilder::loadQuery ( )

slot

Load query from the XML file.

Since

QGIS 3.16

Definition at line 503 of file qgsquerybuilder.cpp.

loadQueryFromFile()

bool QgsQueryBuilder::loadQueryFromFile ( QString &  subset )

static

Load query from the XML file.

Since

QGIS 3.26

Definition at line 513 of file qgsquerybuilder.cpp.

reject

void QgsQueryBuilder::reject ( )

overrideslot

Definition at line 301 of file qgsquerybuilder.cpp.

saveQuery

void QgsQueryBuilder::saveQuery ( )

slot

Save query to the XML file.

Since

QGIS 3.16

Definition at line 460 of file qgsquerybuilder.cpp.

saveQueryToFile()

bool QgsQueryBuilder::saveQueryToFile ( const QString &  subset )

static

Save query to the XML file.

Since

QGIS 3.26

Definition at line 466 of file qgsquerybuilder.cpp.

setDatasourceDescription

void QgsQueryBuilder::setDatasourceDescription ( const QString &  uri )

slot

Definition at line 450 of file qgsquerybuilder.cpp.

setSql()

void QgsQueryBuilder::setSql

(

const QString &

sqlStatement

)

Set the sql statement to display in the dialog.

Definition at line 356 of file qgsquerybuilder.cpp.

setSubsetString()

void QgsQueryBuilder::setSubsetString ( const QString &  subsetString )

inlineoverridevirtual

Sets a subset string into the dialog.

Implements QgsSubsetStringEditorInterface.

Definition at line 67 of file qgsquerybuilder.h.

showEvent()

void QgsQueryBuilder::showEvent ( QShowEvent *  event )

override

Definition at line 131 of file qgsquerybuilder.cpp.

sql()

QString QgsQueryBuilder::sql

(

)

const

Returns the sql statement entered in the dialog.

Definition at line 351 of file qgsquerybuilder.cpp.

subsetString()

QString QgsQueryBuilder::subsetString ( ) const

inlineoverridevirtual

Returns the subset string entered in the dialog.

Implements QgsSubsetStringEditorInterface.

Definition at line 66 of file qgsquerybuilder.h.

test

void QgsQueryBuilder::test ( )

virtualslot

The default implementation tests that the constructed sql statement to see if the vector layer data provider likes it.

The number of rows that would be returned is displayed in a message box. The test uses a "select count(*) from ..." query to test the SQL statement.

Definition at line 247 of file qgsquerybuilder.cpp.

Friends And Related Symbol Documentation

TestQgsQueryBuilder

friend class TestQgsQueryBuilder

friend

Definition at line 197 of file qgsquerybuilder.h.

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

• /build/qgis-3.99.0+git20250718+f78f5286a64+99sid/src/gui/qgsquerybuilder.h
• /build/qgis-3.99.0+git20250718+f78f5286a64+99sid/src/gui/qgsquerybuilder.cpp