make SEA backend methods return SeaResultSet

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

Author: varun-edachali-dbx

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

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import logging
 import time
 import re
@@ -15,7 +17,7 @@
 
 if TYPE_CHECKING:
     from databricks.sql.client import Cursor
-    from databricks.sql.result_set import ResultSet
+    from databricks.sql.result_set import SeaResultSet
 
 from databricks.sql.backend.databricks_client import DatabricksClient
 from databricks.sql.backend.types import (
@@ -401,12 +403,12 @@ def execute_command(
         max_rows: int,
         max_bytes: int,
         lz4_compression: bool,
-        cursor: "Cursor",
+        cursor: Cursor,
         use_cloud_fetch: bool,
         parameters: List[Dict[str, Any]],
         async_op: bool,
         enforce_embedded_schema_correctness: bool,
-    ) -> Union["ResultSet", None]:
+    ) -> Union[SeaResultSet, None]:
         """
         Execute a SQL command using the SEA backend.
 
@@ -573,8 +575,8 @@ def get_query_state(self, command_id: CommandId) -> CommandState:
     def get_execution_result(
         self,
         command_id: CommandId,
-        cursor: "Cursor",
-    ) -> "ResultSet":
+        cursor: Cursor,
+    ) -> SeaResultSet:
         """
         Get the result of a command execution.
 
@@ -583,7 +585,7 @@ def get_execution_result(
             cursor: Cursor executing the command
 
         Returns:
-            ResultSet: A SeaResultSet instance with the execution results
+            SeaResultSet: A SeaResultSet instance with the execution results
 
         Raises:
             ValueError: If the command ID is invalid
@@ -627,8 +629,8 @@ def get_catalogs(
         session_id: SessionId,
         max_rows: int,
         max_bytes: int,
-        cursor: "Cursor",
-    ) -> "ResultSet":
+        cursor: Cursor,
+    ) -> SeaResultSet:
         """Get available catalogs by executing 'SHOW CATALOGS'."""
         result = self.execute_command(
             operation=MetadataCommands.SHOW_CATALOGS.value,
@@ -650,10 +652,10 @@ def get_schemas(
         session_id: SessionId,
         max_rows: int,
         max_bytes: int,
-        cursor: "Cursor",
+        cursor: Cursor,
         catalog_name: Optional[str] = None,
         schema_name: Optional[str] = None,
-    ) -> "ResultSet":
+    ) -> SeaResultSet:
         """Get schemas by executing 'SHOW SCHEMAS IN catalog [LIKE pattern]'."""
         if not catalog_name:
             raise ValueError("Catalog name is required for get_schemas")
@@ -683,12 +685,12 @@ def get_tables(
         session_id: SessionId,
         max_rows: int,
         max_bytes: int,
-        cursor: "Cursor",
+        cursor: Cursor,
         catalog_name: Optional[str] = None,
         schema_name: Optional[str] = None,
         table_name: Optional[str] = None,
         table_types: Optional[List[str]] = None,
-    ) -> "ResultSet":
+    ) -> SeaResultSet:
         """Get tables by executing 'SHOW TABLES IN catalog [SCHEMA LIKE pattern] [LIKE pattern]'."""
         operation = (
             MetadataCommands.SHOW_TABLES_ALL_CATALOGS.value
@@ -718,12 +720,6 @@ def get_tables(
         )
         assert result is not None, "execute_command returned None in synchronous mode"
 
-        from databricks.sql.result_set import SeaResultSet
-
-        assert isinstance(
-            result, SeaResultSet
-        ), "execute_command returned a non-SeaResultSet"
-
         # Apply client-side filtering by table_types
         from databricks.sql.backend.sea.utils.filters import ResultSetFilter
 
@@ -736,12 +732,12 @@ def get_columns(
         session_id: SessionId,
         max_rows: int,
         max_bytes: int,
-        cursor: "Cursor",
+        cursor: Cursor,
         catalog_name: Optional[str] = None,
         schema_name: Optional[str] = None,
         table_name: Optional[str] = None,
         column_name: Optional[str] = None,
-    ) -> "ResultSet":
+    ) -> SeaResultSet:
         """Get columns by executing 'SHOW COLUMNS IN CATALOG catalog [SCHEMA LIKE pattern] [TABLE LIKE pattern] [LIKE pattern]'."""
         if not catalog_name:
             raise ValueError("Catalog name is required for get_columns")