oracle provider: allow switching workspaces through property

(cherry picked from commit 2dc448dfb8c568c20e69fc9e3955e5df63d9a880)

Author: jef-n

src/providers/oracle/qgsoracleprovider.cpp

@@ -207,6 +207,35 @@ QgsOracleProvider::~QgsOracleProvider()
   disconnectDb();
 }
 
+QString QgsOracleProvider::getWorkspace() const
+{
+  return mUri.param( "dbworkspace" );
+}
+
+void QgsOracleProvider::setWorkspace( const QString &workspace )
+{
+  QgsDataSourceUri prevUri( mUri );
+
+  disconnectDb();
+
+  if ( workspace.isEmpty() )
+    mUri.removeParam( "dbworkspace" );
+  else
+    mUri.setParam( "dbworkspace", workspace );
+
+  mConnection = QgsOracleConn::connectDb( mUri );
+  if ( !mConnection )
+  {
+    mUri = prevUri;
+    QgsDebugMsg( QString( "restoring previous uri:%1" ).arg( mUri.uri() ) );
+    mConnection = QgsOracleConn::connectDb( mUri );
+  }
+  else
+  {
+    setDataSourceUri( mUri.uri() );
+  }
+}
+
 QgsAbstractFeatureSource *QgsOracleProvider::featureSource() const
 {
   return new QgsOracleFeatureSource( this );
@@ -2381,7 +2410,7 @@ bool QgsOracleProvider::getGeometryDetails()
     }
 
     if ( exec( qry, QString( mUseEstimatedMetadata
-                             ?  "SELECT DISTINCT gtype FROM (SELECT t.%1.sdo_gtype AS gtype FROM %2 t WHERE t.%1 IS NOT NULL AND rownum<1000) WHERE rownum<=2"
+                             ?  "SELECT DISTINCT gtype FROM (SELECT t.%1.sdo_gtype AS gtype FROM %2 t WHERE t.%1 IS NOT NULL AND rownum<100) WHERE rownum<=2"
                              :  "SELECT DISTINCT t.%1.sdo_gtype FROM %2 t WHERE t.%1 IS NOT NULL AND rownum<=2" ).arg( quotedIdentifier( geomCol ) ).arg( mQuery ) ) )
     {
       if ( qry.next() )

src/providers/oracle/qgsoracleprovider.h

@@ -56,6 +56,7 @@ enum QgsOraclePrimaryKeyType
 class QgsOracleProvider : public QgsVectorDataProvider
 {
     Q_OBJECT
+    Q_PROPERTY( QString workspace READ getWorkspace WRITE setWorkspace )
 
   public:
 
@@ -283,6 +284,16 @@ class QgsOracleProvider : public QgsVectorDataProvider
      */
     virtual bool isSaveAndLoadStyleToDBSupported() const override { return true; }
 
+    /**
+     * Switch to oracle workspace
+     */
+    void setWorkspace( const QString &workspace );
+
+    /**
+     * Retrieve oracle workspace name
+     */
+    QString getWorkspace() const;
+
   private:
     QString whereClause( QgsFeatureId featureId ) const;
     QString pkParamWhereClause() const;