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." );
99QgsJoinByAttributeAlgorithm *QgsJoinByAttributeAlgorithm::createInstance()
const
101 return new QgsJoinByAttributeAlgorithm();
106 const int joinMethod = parameterAsEnum( parameters, QStringLiteral(
"METHOD" ), context );
107 const bool discardNonMatching = parameterAsBoolean( parameters, QStringLiteral(
"DISCARD_NONMATCHING" ), context );
109 std::unique_ptr< QgsProcessingFeatureSource > input( parameterAsSource( parameters, QStringLiteral(
"INPUT" ), context ) );
113 std::unique_ptr< QgsProcessingFeatureSource > input2( parameterAsSource( parameters, QStringLiteral(
"INPUT_2" ), context ) );
117 const QString prefix = parameterAsString( parameters, QStringLiteral(
"PREFIX" ), context );
119 const QString field1Name = parameterAsString( parameters, QStringLiteral(
"FIELD" ), context );
120 const QString field2Name = parameterAsString( parameters, QStringLiteral(
"FIELD_2" ), context );
121 const QStringList fieldsToCopy = parameterAsStrings( parameters, QStringLiteral(
"FIELDS_TO_COPY" ), context );
123 const int joinField1Index = input->fields().lookupField( field1Name );
124 const int joinField2Index = input2->fields().lookupField( field2Name );
125 if ( joinField1Index < 0 || joinField2Index < 0 )
130 if ( fieldsToCopy.empty() )
132 outFields2 = input2->fields();
133 fields2Indices.reserve( outFields2.
count() );
134 for (
int i = 0; i < outFields2.
count(); ++i )
141 fields2Indices.reserve( fieldsToCopy.count() );
142 for (
const QString &field : fieldsToCopy )
144 const int index = input2->fields().
lookupField( field );
147 fields2Indices << index;
148 outFields2.
append( input2->fields().at( index ) );
153 if ( !prefix.isEmpty() )
155 for (
int i = 0; i < outFields2.
count(); ++i )
157 outFields2.
rename( i, prefix + outFields2[ i ].name() );
162 fields2Fetch << joinField2Index;
167 std::unique_ptr< QgsFeatureSink > sink( parameterAsSink( parameters, QStringLiteral(
"OUTPUT" ), context, dest, outFields,
169 if ( parameters.value( QStringLiteral(
"OUTPUT" ) ).isValid() && !sink )
172 QString destNonMatching1;
173 std::unique_ptr< QgsFeatureSink > sinkNonMatching1( parameterAsSink( parameters, QStringLiteral(
"NON_MATCHING" ), context, destNonMatching1, input->fields(),
175 if ( parameters.value( QStringLiteral(
"NON_MATCHING" ) ).isValid() && !sinkNonMatching1 )
179 QMultiHash< QVariant, QgsAttributes > input2AttributeCache;
181 double step = input2->featureCount() > 0 ? 50.0 / input2->featureCount() : 1;
194 if ( joinMethod == 1 && input2AttributeCache.contains( feat.
attribute( joinField2Index ) ) )
199 for (
int j = 0; j < feat.
attributes().count(); ++j )
201 if ( ! fields2Indices.contains( j ) )
206 input2AttributeCache.insert( feat.
attribute( joinField2Index ), attributes );
210 step = input->featureCount() > 0 ? 50.0 / input->featureCount() : 1;
213 long long joinedCount = 0;
214 long long unjoinedCount = 0;
225 if ( input2AttributeCache.count( feat.
attribute( joinField1Index ) ) > 0 )
232 QList< QgsAttributes > attributes = input2AttributeCache.values( feat.
attribute( joinField1Index ) );
233 QList< QgsAttributes >::iterator attrsIt = attributes.begin();
234 for ( ; attrsIt != attributes.end(); ++attrsIt )
237 newAttrs.append( *attrsIt );
247 if ( sink && !discardNonMatching )
252 if ( sinkNonMatching1 )
255 throw QgsProcessingException( writeFeatureError( sinkNonMatching1.get(), parameters, QStringLiteral(
"NON_MATCHING" ) ) );
261 feedback->
pushInfo( QObject::tr(
"%n feature(s) from input layer were successfully matched",
nullptr, joinedCount ) );
262 if ( unjoinedCount > 0 )
263 feedback->
reportError( QObject::tr(
"%n feature(s) from input layer could not be matched",
nullptr, unjoinedCount ) );
267 outputs.insert( QStringLiteral(
"OUTPUT" ), dest );
268 outputs.insert( QStringLiteral(
"JOINED_COUNT" ), joinedCount );
269 outputs.insert( QStringLiteral(
"UNJOINABLE_COUNT" ), unjoinedCount );
270 if ( sinkNonMatching1 )
271 outputs.insert( QStringLiteral(
"NON_MATCHING" ), destNonMatching1 );
Wrapper for iterator of features from vector data provider or vector layer.
bool nextFeature(QgsFeature &f)
This class wraps a request for features to a vector layer (or directly its vector data provider).
@ NoGeometry
Geometry is not required. It may still be returned if e.g. required for a filter condition.
@ 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.
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, FieldOrigin origin=OriginProvider, int originIndex=-1)
Appends a field. The field must have unique name, otherwise it is rejected (returns false)
int count() const
Returns number of items.
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.
@ FlagSkipGeometryValidityChecks
Invalid geometry checks should always be skipped. This flag can be useful for algorithms which always...
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).
@ TypeVector
Tables (i.e. vector layers with or without geometry). When used for a sink this indicates the sink ha...
@ TypeVectorAnyGeometry
Any vector layer with geometry.
QList< int > QgsAttributeList