fix: Update prompt handling to allow None values in database queries

db/db.py

@@ -113,7 +113,7 @@ class DatabaseHandler:
             if title:
                 fields.append("title = ?")
                 params.append(title)
-            if prompt:
+            if prompt is not None :
                 fields.append("prompt = ?")
                 params.append(prompt)
             query += ", ".join(fields) + " WHERE num = ?;"