[Fix] Fix DuckDB datasource creation from Web UI (#3009)

Co-authored-by: honglei <honglei@users.noreply.github.com>

packages/dbgpt-core/src/dbgpt/datasource/rdbms/base.py

@@ -228,7 +228,9 @@ class RDBMSConnector(BaseConnector):
 
         # SQL will raise error with schema
         _schema = (
-            None if self.db_type == DBType.SQLite.value() else self._engine.url.database
+            None
+            if self.db_type in (DBType.SQLite.value(), DBType.DuckDb.value())
+            else self._engine.url.database
         )
         # including view support by adding the views as well as tables to the all
         # tables list if view_support is True

packages/dbgpt-ext/src/dbgpt_ext/datasource/rdbms/conn_duckdb.py

@@ -59,7 +59,7 @@ class DuckDbConnector(RDBMSConnector):
         cls, parameters: DuckDbConnectorParameters
     ) -> "DuckDbConnector":
         """Create a new DuckDBConnector from parameters."""
-        return cls.from_uri(parameters.path)
+        return cls.from_uri(parameters.db_url())
 
     @classmethod
     def from_file_path(