Avoid useless join fetches when joined table is empty

qgis · Jun 4, 2020 · 4145898 · 4145898
1 parent 4e592ae
commit 4145898
Showing 1 changed file with 6 additions and 0 deletions.
diff --git a/src/core/qgsvectorlayerfeatureiterator.cpp b/src/core/qgsvectorlayerfeatureiterator.cpp
@@ -1014,6 +1014,12 @@ void QgsVectorLayerFeatureIterator::FetchJoinInfo::addJoinedAttributesCached( Qg
 
 void QgsVectorLayerFeatureIterator::FetchJoinInfo::addJoinedAttributesDirect( QgsFeature &f, const QVariant &joinValue ) const
 {
+  // Shortcut
+  if ( joinLayer && joinLayer->featureCount() < 1 )
+  {
+    return;
+  }
+
   // no memory cache, query the joined values by setting substring
   QString subsetString;