Fixes #36054 : Fix loss precision when rect filtering in virtual layer

qgis · May 28, 2020 · b0424c3 · b0424c3
1 parent 98603b7
commit b0424c3
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Showing 4 changed files with 66 additions and 13 deletions.
diff --git a/src/providers/virtual/qgsvirtuallayerfeatureiterator.cpp b/src/providers/virtual/qgsvirtuallayerfeatureiterator.cpp
@@ -70,18 +70,20 @@ QgsVirtualLayerFeatureIterator::QgsVirtualLayerFeatureIterator( QgsVirtualLayerF
       wheres << subset;
     }
 
+    QVariantList binded;
     if ( !mSource->mDefinition.uid().isNull() )
     {
       // filters are only available when a column with unique id exists
       if ( mSource->mDefinition.hasDefinedGeometry() && !mFilterRect.isNull() )
       {
         bool do_exact = request.flags() & QgsFeatureRequest::ExactIntersect;
-        QString mbr = QStringLiteral( "%1,%2,%3,%4" ).arg( mFilterRect.xMinimum() ).arg( mFilterRect.yMinimum() ).arg( mFilterRect.xMaximum() ).arg( mFilterRect.yMaximum() );
         wheres << quotedColumn( mSource->mDefinition.geometryField() ) + " is not null";
-        wheres <<  QStringLiteral( "%1Intersects(%2,BuildMbr(%3))" )
+        wheres <<  QStringLiteral( "%1Intersects(%2,BuildMbr(?,?,?,?))" )
                .arg( do_exact ? "" : "Mbr",
-                     quotedColumn( mSource->mDefinition.geometryField() ),
-                     mbr );
+                     quotedColumn( mSource->mDefinition.geometryField() ) );
+
+        binded << mFilterRect.xMinimum() << mFilterRect.yMinimum()
+               << mFilterRect.xMaximum() << mFilterRect.yMaximum();
       }
       else if ( request.filterType() == QgsFeatureRequest::FilterFid )
       {
@@ -208,6 +210,10 @@ QgsVirtualLayerFeatureIterator::QgsVirtualLayerFeatureIterator( QgsVirtualLayerF
     }
 
     mQuery.reset( new Sqlite::Query( mSource->mSqlite, mSqlQuery ) );
+    for ( QVariant toBind : binded )
+    {
+      mQuery->bind( toBind );
+    }
 
     mFid = 0;
   }

diff --git a/src/providers/virtual/qgsvirtuallayersqlitehelper.cpp b/src/providers/virtual/qgsvirtuallayersqlitehelper.cpp
@@ -15,6 +15,7 @@ email                : hugo dot mercier at oslandia dot com
  ***************************************************************************/
 
 #include <QString>
+#include <QVariant>
 
 #include <stdexcept>
 
@@ -118,20 +119,44 @@ namespace Sqlite
 
   int Query::step() { return sqlite3_step( stmt_ ); }
 
-  Query &Query::bind( const QString &str, int idx )
+  Query &Query::bind( const QVariant &value, int idx )
   {
-    QByteArray ba( str.toUtf8() );
-    int r = sqlite3_bind_text( stmt_, idx, ba.constData(), ba.size(), SQLITE_TRANSIENT );
-    if ( r )
+    switch ( value.type() )
     {
-      throw std::runtime_error( sqlite3_errmsg( db_ ) );
+      case QVariant::String:
+      {
+        QByteArray ba( value.toString().toUtf8() );
+        int r = sqlite3_bind_text( stmt_, idx, ba.constData(), ba.size(), SQLITE_TRANSIENT );
+        if ( r )
+        {
+          throw std::runtime_error( sqlite3_errmsg( db_ ) );
+        }
+        return *this;
+      }
+
+      case QVariant::Double:
+      {
+        bool ok; // no reason to fail double conversion
+        double dbl = value.toDouble( &ok );
+        int r = sqlite3_bind_double( stmt_, idx, dbl );
+        if ( r )
+        {
+          throw std::runtime_error( sqlite3_errmsg( db_ ) );
+        }
+        return *this;
+      }
+
+      default:
+        // Unsupported type
+        Q_ASSERT( false );
     }
+
     return *this;
   }
 
-  Query &Query::bind( const QString &str )
+  Query &Query::bind( const QVariant &value )
   {
-    return bind( str, nBind_++ );
+    return bind( value, nBind_++ );
   }
 
   void Query::exec( sqlite3 *db, const QString &sql )

diff --git a/src/providers/virtual/qgsvirtuallayersqlitehelper.h b/src/providers/virtual/qgsvirtuallayersqlitehelper.h
@@ -60,8 +60,8 @@ namespace Sqlite
 
       int step();
 
-      Query &bind( const QString &str, int idx );
-      Query &bind( const QString &str );
+      Query &bind( const QVariant &value, int idx );
+      Query &bind( const QVariant &value );
 
       static void exec( sqlite3 *db, const QString &sql );
 

diff --git a/tests/src/python/test_provider_virtual.py b/tests/src/python/test_provider_virtual.py
@@ -1142,6 +1142,28 @@ def testUpdatedFields(self):
 
         QgsProject.instance().removeMapLayer(ml)
 
+    def test_filter_rect_precise(self):
+
+        # Check if don't lost precision when filtering on rect (see https://github.com/qgis/QGIS/issues/36054)
+
+        pl = QgsVectorLayer(os.path.join(self.testDataDir, "points.shp"), "points", "ogr")
+        self.assertTrue(pl.isValid())
+        QgsProject.instance().addMapLayer(pl)
+
+        query = toPercent("SELECT * FROM points")
+        vl = QgsVectorLayer("?query=%s&uid=OBJECTID" % (query), "vl", "virtual")
+        self.assertEqual(vl.isValid(), True)
+        self.assertEqual(vl.dataProvider().featureCount(), 17)
+
+        # Take an extent where east farthest point is excluded and second farthest east is on the edge
+        # and should be returned
+        extent = QgsRectangle(-117.23257418909581418, 22.80020703933767834, -85.6521739130433276, 46.87198067632875365)
+        r = QgsFeatureRequest(extent)
+        features = [feature for feature in vl.getFeatures(r)]
+        self.assertEqual(len(features), 16)
+
+        QgsProject.instance().removeMapLayer(pl)
+
 
 if __name__ == '__main__':
     unittest.main()