clean up conversion code

Signed-off-by: varun-edachali-dbx <varun.edachali@databricks.com>

Author: varun-edachali-dbx

src/databricks/sql/backend/sea/result_set.py

@@ -204,12 +204,8 @@ def fetchmany_arrow(self, size: int) -> "pyarrow.Table":
 
         results = self.results.next_n_rows(size)
         if isinstance(self.results, JsonQueue):
-            # Transform JSON first, then convert to Arrow
-            transformed_json = self._normalise_json_metadata_cols(results)
-            results = self._convert_json_to_arrow_table(transformed_json)
-        else:
-            # Transform Arrow table directly
-            results = self._normalise_arrow_metadata_cols(results)
+            results = self._convert_json_to_arrow_table(results)
+        results = self._normalise_arrow_metadata_cols(results)
 
         self._next_row_index += results.num_rows
 
@@ -222,12 +218,8 @@ def fetchall_arrow(self) -> "pyarrow.Table":
 
         results = self.results.remaining_rows()
         if isinstance(self.results, JsonQueue):
-            # Transform JSON first, then convert to Arrow
-            transformed_json = self._normalise_json_metadata_cols(results)
-            results = self._convert_json_to_arrow_table(transformed_json)
-        else:
-            # Transform Arrow table directly
-            results = self._normalise_arrow_metadata_cols(results)
+            results = self._convert_json_to_arrow_table(results)
+        results = self._normalise_arrow_metadata_cols(results)
 
         self._next_row_index += results.num_rows
 

src/databricks/sql/backend/sea/utils/conversion.py

@@ -159,10 +159,6 @@ def convert_value(
             The converted value in the appropriate Python type
         """
 
-        # Handle None values directly
-        if value is None:
-            return None
-
         sql_type = sql_type.lower().strip()
 
         if sql_type not in SqlTypeConverter.TYPE_MAPPING: