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QgsRelation Class Reference

#include <qgsrelation.h>

Classes

class  FieldPair
 Defines a relation between matchin fields of the two involved tables of a relation. More...
 

Public Member Functions

 QgsRelation ()
 Default constructor. More...
 
void addFieldPair (QString referencingField, QString referencedField)
 Add a field pairs which is part of this relation The first element of each pair are the field names fo the foreign key. More...
 
void addFieldPair (FieldPair fieldPair)
 Add a field pairs which is part of this relation The first element of each pair are the field names fo the foreign key. More...
 
QList< FieldPairfieldPairs () const
 Returns the field pairs which form this relation The first element of each pair are the field names fo the foreign key. More...
 
QgsFeatureIterator getRelatedFeatures (const QgsFeature &feature) const
 Creates an iterator which returns all the features on the referencing (child) layer which have a foreign key pointing to the provided feature. More...
 
QgsFeatureRequest getRelatedFeaturesRequest (const QgsFeature &feature) const
 Creates a request to return all the features on the referencing (child) layer which have a foreign key pointing to the provided feature. More...
 
const QString & id () const
 The id. More...
 
bool isValid () const
 Returns the validity of this relation. More...
 
const QString name () const
 
QgsVectorLayerreferencedLayer () const
 Access the referenced (parent) layer. More...
 
QString referencedLayerId () const
 Access the referenced (parent) layer's id. More...
 
QgsVectorLayerreferencingLayer () const
 Access the referencing (child) layer This is the layer which has the field(s) which point to another layer. More...
 
QString referencingLayerId () const
 Access the referencing (child) layer's id This is the layer which has the field(s) which point to another layer. More...
 
void setReferencedLayer (QString id)
 Set the referenced layer id. More...
 
void setReferencingLayer (QString id)
 Set the referencing layer id. More...
 
void setRelationId (QString id)
 Set a name for this relation. More...
 
void setRelationName (QString name)
 Set a name for this relation. More...
 
void writeXML (QDomNode &node, QDomDocument &doc) const
 Writes a relation to an XML structure. More...
 

Static Public Member Functions

static QgsRelation createFromXML (const QDomNode &node)
 Creates a relation from an XML structure. More...
 

Protected Member Functions

void runChecks ()
 
void updateRelationStatus ()
 

Detailed Description

Definition at line 28 of file qgsrelation.h.

Constructor & Destructor Documentation

QgsRelation::QgsRelation ( )

Default constructor.

Creates an invalid relation.

Definition at line 23 of file qgsrelation.cpp.

Member Function Documentation

void QgsRelation::addFieldPair ( QString  referencingField,
QString  referencedField 
)

Add a field pairs which is part of this relation The first element of each pair are the field names fo the foreign key.

The second element of each pair are the field names of the matching primary key.

Parameters
referencingFieldThe field name on the referencing layer (FK)
referencedFieldThe field name on the referenced layer (PK)

Definition at line 135 of file qgsrelation.cpp.

void QgsRelation::addFieldPair ( QgsRelation::FieldPair  fieldPair)

Add a field pairs which is part of this relation The first element of each pair are the field names fo the foreign key.

The second element of each pair are the field names of the matching primary key.

Parameters
fieldPairA pair of two strings
Note
not available in python bindings

Definition at line 141 of file qgsrelation.cpp.

QgsRelation QgsRelation::createFromXML ( const QDomNode &  node)
static

Creates a relation from an XML structure.

Used for reading .qgs projects.

Parameters
nodeThe dom node containing the relation information
Returns
A relation

Definition at line 30 of file qgsrelation.cpp.

QList< QgsRelation::FieldPair > QgsRelation::fieldPairs ( ) const

Returns the field pairs which form this relation The first element of each pair are the field names fo the foreign key.

The second element of each pair are the field names of the matching primary key.

Returns
The fields forming the relation

Definition at line 214 of file qgsrelation.cpp.

QgsFeatureIterator QgsRelation::getRelatedFeatures ( const QgsFeature feature) const

Creates an iterator which returns all the features on the referencing (child) layer which have a foreign key pointing to the provided feature.

Parameters
featureA feature from the referenced (parent) layer
Returns
An iterator with all the referenced features

Definition at line 147 of file qgsrelation.cpp.

QgsFeatureRequest QgsRelation::getRelatedFeaturesRequest ( const QgsFeature feature) const

Creates a request to return all the features on the referencing (child) layer which have a foreign key pointing to the provided feature.

Parameters
featureA feature from the referenced (parent) layer
Returns
An request for all the referenced features

Definition at line 152 of file qgsrelation.cpp.

const QString & QgsRelation::id ( ) const

The id.

Returns

Definition at line 189 of file qgsrelation.cpp.

bool QgsRelation::isValid ( ) const

Returns the validity of this relation.

Don't use the information if it's not valid.

Returns
true if the relation is valid

Definition at line 219 of file qgsrelation.cpp.

const QString QgsRelation::name ( ) const

Definition at line 184 of file qgsrelation.cpp.

QgsVectorLayer * QgsRelation::referencedLayer ( ) const

Access the referenced (parent) layer.

Returns
referenced layer

Definition at line 209 of file qgsrelation.cpp.

QString QgsRelation::referencedLayerId ( ) const

Access the referenced (parent) layer's id.

Returns
The id of the referenced layer

Definition at line 204 of file qgsrelation.cpp.

QgsVectorLayer * QgsRelation::referencingLayer ( ) const

Access the referencing (child) layer This is the layer which has the field(s) which point to another layer.

Returns
The referencing layer

Definition at line 199 of file qgsrelation.cpp.

QString QgsRelation::referencingLayerId ( ) const

Access the referencing (child) layer's id This is the layer which has the field(s) which point to another layer.

Returns
The id of the referencing layer

Definition at line 194 of file qgsrelation.cpp.

void QgsRelation::runChecks ( )
protected

Definition at line 255 of file qgsrelation.cpp.

void QgsRelation::setReferencedLayer ( QString  id)

Set the referenced layer id.

This layer will be searched in the registry.

Parameters
id

Definition at line 128 of file qgsrelation.cpp.

void QgsRelation::setReferencingLayer ( QString  id)

Set the referencing layer id.

This layer will be searched in the registry.

Parameters
id

Definition at line 121 of file qgsrelation.cpp.

void QgsRelation::setRelationId ( QString  id)

Set a name for this relation.

Parameters
id

Definition at line 111 of file qgsrelation.cpp.

void QgsRelation::setRelationName ( QString  name)

Set a name for this relation.

Parameters
name

Definition at line 116 of file qgsrelation.cpp.

void QgsRelation::updateRelationStatus ( )
protected

Definition at line 224 of file qgsrelation.cpp.

void QgsRelation::writeXML ( QDomNode &  node,
QDomDocument &  doc 
) const

Writes a relation to an XML structure.

Used for saving .qgs projects

Parameters
nodeThe parent node in which the relation will be created
docThe document in which the relation will be saved

Definition at line 92 of file qgsrelation.cpp.


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