23QString QgsJoinByAttributeAlgorithm::name()
const
25 return QStringLiteral(
"joinattributestable" );
28QString QgsJoinByAttributeAlgorithm::displayName()
const
30 return QObject::tr(
"Join attributes by field value" );
33QStringList QgsJoinByAttributeAlgorithm::tags()
const
35 return QObject::tr(
"join,connect,attributes,values,fields,tables" ).split(
',' );
38QString QgsJoinByAttributeAlgorithm::group()
const
40 return QObject::tr(
"Vector general" );
43QString QgsJoinByAttributeAlgorithm::groupId()
const
45 return QStringLiteral(
"vectorgeneral" );
48void QgsJoinByAttributeAlgorithm::initAlgorithm(
const QVariantMap & )
51 methods << QObject::tr(
"Create separate feature for each matching feature (one-to-many)" )
52 << QObject::tr(
"Take attributes of the first matching feature only (one-to-one)" );
57 QObject::tr(
"Table field" ), QVariant(), QStringLiteral(
"INPUT" ) ) );
62 QObject::tr(
"Table field 2" ), QVariant(), QStringLiteral(
"INPUT_2" ) ) );
65 QObject::tr(
"Layer 2 fields to copy (leave empty to copy all fields)" ),
70 QObject::tr(
"Join type" ),
71 methods,
false, 1 ) );
73 QObject::tr(
"Discard records which could not be joined" ),
77 QObject::tr(
"Joined field prefix" ), QVariant(),
false,
true ) );
81 std::unique_ptr< QgsProcessingParameterFeatureSink > nonMatchingSink = std::make_unique< QgsProcessingParameterFeatureSink >(
85 addParameter( nonMatchingSink.release() );
87 addOutput(
new QgsProcessingOutputNumber( QStringLiteral(
"JOINED_COUNT" ), QObject::tr(
"Number of joined features from input table" ) ) );
88 addOutput(
new QgsProcessingOutputNumber( QStringLiteral(
"UNJOINABLE_COUNT" ), QObject::tr(
"Number of unjoinable features from input table" ) ) );
91QString QgsJoinByAttributeAlgorithm::shortHelpString()
const
93 return QObject::tr(
"This algorithm takes an input vector layer and creates a new vector layer that is an extended version of the "
94 "input one, with additional attributes in its attribute table.\n\n"
95 "The additional attributes and their values are taken from a second vector layer. An attribute is selected "
96 "in each of them to define the join criteria." );
104QgsJoinByAttributeAlgorithm *QgsJoinByAttributeAlgorithm::createInstance()
const
106 return new QgsJoinByAttributeAlgorithm();
111 const int joinMethod = parameterAsEnum( parameters, QStringLiteral(
"METHOD" ), context );
112 const bool discardNonMatching = parameterAsBoolean( parameters, QStringLiteral(
"DISCARD_NONMATCHING" ), context );
114 std::unique_ptr< QgsProcessingFeatureSource > input( parameterAsSource( parameters, QStringLiteral(
"INPUT" ), context ) );
118 std::unique_ptr< QgsProcessingFeatureSource > input2( parameterAsSource( parameters, QStringLiteral(
"INPUT_2" ), context ) );
122 const QString prefix = parameterAsString( parameters, QStringLiteral(
"PREFIX" ), context );
124 const QString field1Name = parameterAsString( parameters, QStringLiteral(
"FIELD" ), context );
125 const QString field2Name = parameterAsString( parameters, QStringLiteral(
"FIELD_2" ), context );
126 const QStringList fieldsToCopy = parameterAsStrings( parameters, QStringLiteral(
"FIELDS_TO_COPY" ), context );
128 const int joinField1Index = input->fields().lookupField( field1Name );
129 if ( joinField1Index < 0 )
130 throw QgsProcessingException( QObject::tr(
"Invalid join field from layer 1: “%1” does not exist" ).arg( field1Name ) );
132 const int joinField2Index = input2->fields().lookupField( field2Name );
133 if ( joinField2Index < 0 )
134 throw QgsProcessingException( QObject::tr(
"Invalid join field from layer 2: “%1” does not exist" ).arg( field2Name ) );
138 if ( fieldsToCopy.empty() )
140 outFields2 = input2->fields();
141 fields2Indices.reserve( outFields2.
count() );
142 for (
int i = 0; i < outFields2.
count(); ++i )
149 fields2Indices.reserve( fieldsToCopy.count() );
150 for (
const QString &field : fieldsToCopy )
152 const int index = input2->fields().
lookupField( field );
155 fields2Indices << index;
156 outFields2.
append( input2->fields().at( index ) );
161 if ( !prefix.isEmpty() )
163 for (
int i = 0; i < outFields2.
count(); ++i )
165 outFields2.
rename( i, prefix + outFields2[ i ].name() );
170 fields2Fetch << joinField2Index;
175 std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral(
"OUTPUT" ), context, dest, outFields,
177 if ( parameters.value( QStringLiteral(
"OUTPUT" ) ).isValid() && !sink )
180 QString destNonMatching1;
181 std::unique_ptr< QgsFeatureSink > sinkNonMatching1( parameterAsSink( parameters, QStringLiteral(
"NON_MATCHING" ), context, destNonMatching1, input->fields(),
183 if ( parameters.value( QStringLiteral(
"NON_MATCHING" ) ).isValid() && !sinkNonMatching1 )
187 QMultiHash< QVariant, QgsAttributes > input2AttributeCache;
189 double step = input2->featureCount() > 0 ? 50.0 / input2->featureCount() : 1;
202 if ( joinMethod == 1 && input2AttributeCache.contains( feat.
attribute( joinField2Index ) ) )
208 for (
int j = 0; j < attributeCount; ++j )
210 if ( ! fields2Indices.contains( j ) )
215 input2AttributeCache.insert( feat.
attribute( joinField2Index ), attributes );
219 step = input->featureCount() > 0 ? 50.0 / input->featureCount() : 1;
222 long long joinedCount = 0;
223 long long unjoinedCount = 0;
234 if ( input2AttributeCache.count( feat.
attribute( joinField1Index ) ) > 0 )
241 QList< QgsAttributes > attributes = input2AttributeCache.values( feat.
attribute( joinField1Index ) );
242 QList< QgsAttributes >::iterator attrsIt = attributes.begin();
243 for ( ; attrsIt != attributes.end(); ++attrsIt )
246 newAttrs.append( *attrsIt );
256 if ( sink && !discardNonMatching )
261 if ( sinkNonMatching1 )
264 throw QgsProcessingException( writeFeatureError( sinkNonMatching1.get(), parameters, QStringLiteral(
"NON_MATCHING" ) ) );
270 feedback->
pushInfo( QObject::tr(
"%n feature(s) from input layer were successfully matched",
nullptr, joinedCount ) );
271 if ( unjoinedCount > 0 )
272 feedback->
reportError( QObject::tr(
"%n feature(s) from input layer could not be matched",
nullptr, unjoinedCount ) );
276 outputs.insert( QStringLiteral(
"OUTPUT" ), dest );
277 outputs.insert( QStringLiteral(
"JOINED_COUNT" ), joinedCount );
278 outputs.insert( QStringLiteral(
"UNJOINABLE_COUNT" ), unjoinedCount );
279 if ( sinkNonMatching1 )
280 outputs.insert( QStringLiteral(
"NON_MATCHING" ), destNonMatching1 );
@ Vector
Tables (i.e. vector layers with or without geometry). When used for a sink this indicates the sink ha...
@ VectorAnyGeometry
Any vector layer with geometry.
@ NoGeometry
Geometry is not required. It may still be returned if e.g. required for a filter condition.
@ RegeneratesPrimaryKey
Algorithm always drops any existing primary keys or FID values and regenerates them in outputs.
QFlags< ProcessingAlgorithmDocumentationFlag > ProcessingAlgorithmDocumentationFlags
Flags describing algorithm behavior for documentation purposes.
@ SkipGeometryValidityChecks
Invalid geometry checks should always be skipped. This flag can be useful for algorithms which always...
Wrapper for iterator of features from vector data provider or vector layer.
bool nextFeature(QgsFeature &f)
Fetch next feature and stores in f, returns true on success.
This class wraps a request for features to a vector layer (or directly its vector data provider).
@ FastInsert
Use faster inserts, at the cost of updating the passed features to reflect changes made at the provid...
@ RegeneratePrimaryKey
This flag indicates, that a primary key field cannot be guaranteed to be unique and the sink should i...
The feature class encapsulates a single feature including its unique ID, geometry and a list of field...
void setAttributes(const QgsAttributes &attrs)
Sets the feature's attributes.
int attributeCount() const
Returns the number of attributes attached to the feature.
Q_INVOKABLE QVariant attribute(const QString &name) const
Lookup attribute value by attribute name.
bool isCanceled() const
Tells whether the operation has been canceled already.
void setProgress(double progress)
Sets the current progress for the feedback object.
Container of fields for a vector layer.
bool append(const QgsField &field, Qgis::FieldOrigin origin=Qgis::FieldOrigin::Provider, int originIndex=-1)
Appends a field.
Q_INVOKABLE int lookupField(const QString &fieldName) const
Looks up field's index from the field name.
bool rename(int fieldIdx, const QString &name)
Renames a name of field.
Contains information about the context in which a processing algorithm is executed.
Custom exception class for processing related exceptions.
Base class for providing feedback from a processing algorithm.
virtual void pushInfo(const QString &info)
Pushes a general informational message from the algorithm.
virtual void reportError(const QString &error, bool fatalError=false)
Reports that the algorithm encountered an error while executing.
A numeric output for processing algorithms.
A boolean parameter for processing algorithms.
An enum based parameter for processing algorithms, allowing for selection from predefined values.
A feature sink output for processing algorithms.
An input feature source (such as vector layers) parameter for processing algorithms.
A vector layer or feature source field parameter for processing algorithms.
A string parameter for processing algorithms.
static QgsFields combineFields(const QgsFields &fieldsA, const QgsFields &fieldsB, const QString &fieldsBPrefix=QString())
Combines two field lists, avoiding duplicate field names (in a case-insensitive manner).
QList< int > QgsAttributeList