diff --git a/src/blackgui/filters/filterwidget.cpp b/src/blackgui/filters/filterwidget.cpp
index 0aae851b2..2b90db3d4 100644
--- a/src/blackgui/filters/filterwidget.cpp
+++ b/src/blackgui/filters/filterwidget.cpp
@@ -39,6 +39,15 @@ namespace BlackGui
             }
         }
 
+        int CFilterWidget::convertDbId(const QString &candidate)
+        {
+            const QString s = candidate.trimmed();
+            if (s.isEmpty()) { return -1; }
+            bool ok = false;
+            const int id = s.toInt(&ok);
+            return ok && id >= 0 ? id : -1;
+        }
+
         void CFilterWidget::triggerFilter()
         {
             this->ps_filterButtonClicked(CFilterBarButtons::Filter);
@@ -67,6 +76,5 @@ namespace BlackGui
                 break;
             }
         }
-
     } // namespace
 } // namespace
diff --git a/src/blackgui/filters/filterwidget.h b/src/blackgui/filters/filterwidget.h
index 67c8f9969..efe6f6a9d 100644
--- a/src/blackgui/filters/filterwidget.h
+++ b/src/blackgui/filters/filterwidget.h
@@ -57,6 +57,9 @@ namespace BlackGui
             //! Clear the filter form
             virtual void clearForm() = 0;
 
+            //! Convert DB id
+            static int convertDbId(const QString &candidate);
+
         private slots:
             //! Button clicked
             void ps_filterButtonClicked(CFilterBarButtons::FilterButton filterButton);
@@ -64,7 +67,6 @@ namespace BlackGui
             //! Stylesheet changed
             void ps_onStyleSheetChanged();
         };
-
     } // namespace
 } // namespace