Improve handling of estimated metadata (fixes #5227 fixes #5252)

src/providers/mssql/qgsmssqldataitems.cpp

@@ -53,10 +53,14 @@ QgsMssqlConnectionItem::QgsMssqlConnectionItem( QgsDataItem* parent, QString nam
   }
 
   mUseGeometryColumns = settings.value( key + "/geometryColumns", false ).toBool();
+  mUseEstimatedMetadata = settings.value( key + "/estimatedMetadata", false ).toBool();
+  mAllowGeometrylessTables = settings.value( key + "/allowGeometrylessTables", true ).toBool();
 
   mConnInfo =  "dbname='" + mDatabase + "' host=" + mHost + " user='" + mUsername + "' password='" + mPassword + "'";
   if ( !mService.isEmpty() )
     mConnInfo += " service='" + mService + "'";
+  if ( mUseEstimatedMetadata )
+    mConnInfo += " estimatedmetadata=true";
 }
 
 QgsMssqlConnectionItem::~QgsMssqlConnectionItem()

src/providers/mssql/qgsmssqldataitems.h

@@ -81,6 +81,8 @@ class QgsMssqlConnectionItem : public QgsDataCollectionItem
     QString mUsername;
     QString mPassword;
     bool mUseGeometryColumns;
+    bool mUseEstimatedMetadata;
+    bool mAllowGeometrylessTables;
 };
 
 class QgsMssqlSchemaItem : public QgsDataCollectionItem

src/providers/mssql/qgsmssqlprovider.cpp

@@ -59,11 +59,20 @@ QgsMssqlProvider::QgsMssqlProvider( QString uri )
 {
   QgsDataSourceURI anUri = QgsDataSourceURI( uri );
 
+  if ( !anUri.srid().isEmpty() )
+    mSRId = anUri.srid().toInt();
+  else
+    mSRId = -1;
+
+  mWkbType = anUri.wkbType();
+
   mValid = true;
 
   mUseWkb = false;
   mSkipFailures = true;
 
+  mUseEstimatedMetadata = anUri.useEstimatedMetadata();
+
   mDatabase = GetDatabase( anUri.service(), anUri.host(), anUri.database(), anUri.username(), anUri.password() );
 
   if ( !OpenDatabase( mDatabase ) )
@@ -108,9 +117,10 @@ QgsMssqlProvider::QgsMssqlProvider( QString uri )
     if ( !anUri.geometryColumn().isEmpty() )
       mGeometryColName = anUri.geometryColumn();
 
+    if ( mSRId < 0 || mWkbType == QGis::WKBUnknown || mGeometryColName.isEmpty() )
       loadMetadata();
     loadFields();
-    UpdateStatistics();
+    UpdateStatistics( mUseEstimatedMetadata );
 
     if ( mGeometryColName.isEmpty() )
     {
@@ -578,48 +588,44 @@ void QgsMssqlProvider::select( QgsAttributeList fetchAttributes,
 }
 
 // update the extent, feature count, wkb type and srid for this layer
-void QgsMssqlProvider::UpdateStatistics()
+void QgsMssqlProvider::UpdateStatistics( bool estimate )
 {
   mNumberFeatures = 0;
   // get features to calculate the statistics
+  QString statement;
+  if ( estimate )
+  {
+    statement = QString( "select min([%1].STPointN(1).STX), min([%1].STPointN(1).STY), max([%1].STPointN(1).STX), max([%1].STPointN(1).STY), COUNT([%1])" ).arg( mGeometryColName );
+  }
+  else
+  {
+    statement = QString( "select min([%1].STEnvelope().STPointN(1).STX), min([%1].STEnvelope().STPointN(1).STY), max([%1].STEnvelope().STPointN(2).STX), max([%1].STEnvelope().STPointN(2).STY), count([%1])" ).arg( mGeometryColName );
+  }
+
+  if ( mSchemaName.isEmpty() )
+    statement += QString( " from [%1]" ).arg( mTableName );
+  else
+    statement += QString( " from [%1].[%2]" ).arg( mSchemaName, mTableName );
+
   mQuery = QSqlQuery( mDatabase );
   mQuery.setForwardOnly( true );
-  if ( mSchemaName.isEmpty() )
+
-    mQuery.exec( QString( "select [%1] from [%2]" ).arg( mGeometryColName, mTableName ) );
+  if ( !mQuery.exec( statement ) )
-  else
+  {
-    mQuery.exec( QString( "select [%1] from [%2].[%3]" ).arg( mGeometryColName, mSchemaName, mTableName ) );
+    QString msg = mQuery.lastError().text();
+    QgsDebugMsg( msg );
+  }
 
   if ( mQuery.isActive() )
   {
     QgsGeometry geom;
-    while ( mQuery.next() )
+    if ( mQuery.next() )
     {
-      QByteArray ar = mQuery.value( 0 ).toByteArray();
+      mExtent.setXMinimum( mQuery.value( 0 ).toDouble() );
-      unsigned char* wkb = parser.ParseSqlGeometry(( unsigned char* )ar.data(), ar.size() );
+      mExtent.setYMinimum( mQuery.value( 1 ).toDouble() );
-      if ( wkb )
+      mExtent.setXMaximum( mQuery.value( 2 ).toDouble() );
-      {
+      mExtent.setYMaximum( mQuery.value( 3 ).toDouble() );
-        geom.fromWkb( wkb, parser.GetWkbLen() );
+      mNumberFeatures = mQuery.value( 4 ).toInt();
-        QgsRectangle rect = geom.boundingBox();
-
-        if ( mNumberFeatures > 0 )
-        {
-          if ( rect.xMinimum() < mExtent.xMinimum() )
-            mExtent.setXMinimum( rect.xMinimum() );
-          if ( rect.yMinimum() < mExtent.yMinimum() )
-            mExtent.setYMinimum( rect.yMinimum() );
-          if ( rect.xMaximum() > mExtent.xMaximum() )
-            mExtent.setXMaximum( rect.xMaximum() );
-          if ( rect.yMaximum() > mExtent.yMaximum() )
-            mExtent.setYMaximum( rect.yMaximum() );
-        }
-        else
-        {
-          mExtent = rect;
-          mWkbType = geom.wkbType();
-          mSRId = parser.GetSRSId();
-        }
-        ++mNumberFeatures;
-      }
     }
   }
 }
@@ -628,7 +634,7 @@ void QgsMssqlProvider::UpdateStatistics()
 QgsRectangle QgsMssqlProvider::extent()
 {
   if ( mExtent.isEmpty() )
-    UpdateStatistics();
+    UpdateStatistics( mUseEstimatedMetadata );
   return mExtent;
 }
 
@@ -1064,6 +1070,9 @@ int QgsMssqlProvider::capabilities() const
 
 bool QgsMssqlProvider::createSpatialIndex()
 {
+  if ( mUseEstimatedMetadata )
+    UpdateStatistics( false );
+
   mQuery = QSqlQuery( mDatabase );
   mQuery.setForwardOnly( true );
   QString statement;
@@ -1468,6 +1477,7 @@ QgsVectorLayerImport::ImportError QgsMssqlProvider::createEmptyLayer(
 
   // clear any resources hold by the query
   q.clear();
+  q.setForwardOnly( true );
 
   // use the provider to edit the table
   dsUri.setDataSource( schemaName, tableName, geometryColumn, QString(), primaryKey );

src/providers/mssql/qgsmssqlprovider.h

@@ -171,7 +171,7 @@ class QgsMssqlProvider : public QgsVectorDataProvider
     virtual uint fieldCount() const;
 
     /** update the extent, feature count, wkb type and srid for this layer */
-    void UpdateStatistics();
+    void UpdateStatistics( bool estimate );
 
     /**
      * Return a map of indexes with field names for this layer
@@ -302,6 +302,7 @@ class QgsMssqlProvider : public QgsVectorDataProvider
     bool mValid;
 
     bool mUseWkb;
+    bool mUseEstimatedMetadata;
     bool mSkipFailures;
 
     int mGeomType;