Model: Start export model into SQLite database.

* Study: Create table.
* River: Create node and reach table.
* Geometry: Create table only for profileXYZ and pointXYZ.

src/View/MainWindow.py

@@ -213,7 +213,7 @@ class ApplicationWindow(QMainWindow, ListedSubWindow, WindowToolKit):
         Returns:
             Nothing
         """
-        if self.model.filename == "":
+        if self.model.filename is None or self.model.filename == "":
             file_name, _ = QFileDialog.getSaveFileName(
                 self, "Save File",
                 "", "Pamhyr(*.pkl)"
@@ -282,9 +282,9 @@ class ApplicationWindow(QMainWindow, ListedSubWindow, WindowToolKit):
         if self.model is None:
             dialog = QFileDialog(self)
             dialog.setFileMode(QFileDialog.FileMode.ExistingFile)
-            dialog.setDefaultSuffix(".pkl")
+            dialog.setDefaultSuffix(".pamhyr")
             #dialog.setFilter(dialog.filter() | QtCore.QDir.Hidden)
-            dialog.setNameFilters(['PamHyr (*.pkl)'])
+            dialog.setNameFilters(['PamHyr (*.pamhyr)'])
 
             if dialog.exec_():
                 file_name = dialog.selectedFiles()