align description extracted with Thrift

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

Author: varun-edachali-dbx

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

@@ -319,15 +319,23 @@ def _extract_description_from_manifest(
         columns = []
         for col_data in columns_data:
             # Format: (name, type_code, display_size, internal_size, precision, scale, null_ok)
+            name = col_data.get("name", "")
+            type_name = col_data.get("type_name", "")
+            type_name = (
+                type_name[:-5] if type_name.endswith("_TYPE") else type_name
+            ).lower()
+            precision = col_data.get("type_precision")
+            scale = col_data.get("type_scale")
+
             columns.append(
                 (
-                    col_data.get("name", ""),  # name
-                    col_data.get("type_name", ""),  # type_code
+                    name,  # name
+                    type_name,  # type_code
                     None,  # display_size (not provided by SEA)
                     None,  # internal_size (not provided by SEA)
-                    col_data.get("precision"),  # precision
-                    col_data.get("scale"),  # scale
-                    col_data.get("nullable", True),  # null_ok
+                    precision,  # precision
+                    scale,  # scale
+                    None,  # null_ok
                 )
             )
 

tests/unit/test_sea_backend.py

@@ -597,9 +597,8 @@ def test_utility_methods(self, sea_client):
                 {
                     "name": "col1",
                     "type_name": "STRING",
-                    "precision": 10,
-                    "scale": 2,
-                    "nullable": True,
+                    "type_precision": 10,
+                    "type_scale": 2,
                 },
                 {
                     "name": "col2",
@@ -613,13 +612,13 @@ def test_utility_methods(self, sea_client):
         assert description is not None
         assert len(description) == 2
         assert description[0][0] == "col1"  # name
-        assert description[0][1] == "STRING"  # type_code
+        assert description[0][1] == "string"  # type_code
         assert description[0][4] == 10  # precision
         assert description[0][5] == 2  # scale
-        assert description[0][6] is True  # null_ok
+        assert description[0][6] is None  # null_ok
         assert description[1][0] == "col2"  # name
-        assert description[1][1] == "INT"  # type_code
-        assert description[1][6] is False  # null_ok
+        assert description[1][1] == "int"  # type_code
+        assert description[1][6] is None  # null_ok
 
     def test_filter_session_configuration(self):
         """Test that _filter_session_configuration converts all values to strings."""