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. More...
void	reject () override
void	saveQuery ()
	Save query to the XML file. More...
void	setDatasourceDescription (const QString &uri)
void	test ()
	Test the constructed sql statement to see if the vector layer data provider likes it. More...

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. More...
void	setSql (const QString &sqlStatement)
void	showEvent (QShowEvent *event) override
QString	sql ()

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 42 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 38 of file qgsquerybuilder.cpp.

Member Function Documentation

accept

void QgsQueryBuilder::accept ( )

overrideslot

Definition at line 269 of file qgsquerybuilder.cpp.

clear

void QgsQueryBuilder::clear ( )

slot

Definition at line 433 of file qgsquerybuilder.cpp.

loadQuery

void QgsQueryBuilder::loadQuery ( )

slot

Load query from the XML file.

Since

QGIS 3.16

Definition at line 492 of file qgsquerybuilder.cpp.

reject

void QgsQueryBuilder::reject ( )

overrideslot

Definition at line 296 of file qgsquerybuilder.cpp.

saveQuery

void QgsQueryBuilder::saveQuery ( )

slot

Save query to the XML file.

Since

QGIS 3.16

Definition at line 456 of file qgsquerybuilder.cpp.

setDatasourceDescription

void QgsQueryBuilder::setDatasourceDescription ( const QString &  uri )

slot

Definition at line 446 of file qgsquerybuilder.cpp.

setSql()

void QgsQueryBuilder::setSql

(

const QString &

sqlStatement

)

Definition at line 351 of file qgsquerybuilder.cpp.

showEvent()

void QgsQueryBuilder::showEvent ( QShowEvent *  event )

override

Definition at line 101 of file qgsquerybuilder.cpp.

sql()

QString QgsQueryBuilder::sql

(

)

Definition at line 346 of file qgsquerybuilder.cpp.

test

void QgsQueryBuilder::test ( )

slot

Test 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 228 of file qgsquerybuilder.cpp.

---

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

• /build/qgis-3.16.0+99unstable/src/gui/qgsquerybuilder.h
• /build/qgis-3.16.0+99unstable/src/gui/qgsquerybuilder.cpp