properly set null for all dialects

Author: themisvaltinos

sqlmesh/core/engine_adapter/base.py

@@ -1773,7 +1773,11 @@ def remove_managed_columns(
                     if truncate
                     else exp.select(
                         *(
-                            exp.Null().as_(col) if col == valid_to_col.name else exp.column(col)
+                            to_time_column(
+                                exp.null(), time_data_type, self.dialect, nullable=True
+                            ).as_(col)
+                            if col == valid_to_col.name
+                            else exp.column(col)
                             for col in columns_to_types
                         ),
                         exp.true().as_("_exists"),
@@ -1783,7 +1787,7 @@ def remove_managed_columns(
                         exp.and_(
                             valid_from_col <= cleanup_ts,
                             exp.or_(
-                                valid_to_col.is_(exp.Null()),
+                                valid_to_col.is_(exp.null()),
                                 valid_to_col >= cleanup_ts,
                             ),
                         )

tests/core/engine_adapter/test_base.py

@@ -1264,7 +1264,7 @@ def test_scd_type_2_by_time(make_mocked_engine_adapter: t.Callable):
     "price",
     "test_UPDATED_at",
     "test_valid_from",
-    NULL AS "test_valid_to",
+    CAST(NULL AS TIMESTAMP) AS "test_valid_to",
     TRUE AS "_exists"
   FROM "target"
   WHERE "test_valid_from" <= CAST('2020-01-01 00:00:00' AS TIMESTAMP)
@@ -1464,7 +1464,7 @@ def test_scd_type_2_by_time_no_invalidate_hard_deletes(make_mocked_engine_adapte
     "price",
     "test_updated_at",
     "test_valid_from",
-    NULL AS "test_valid_to",
+    CAST(NULL AS TIMESTAMP) AS "test_valid_to",
     TRUE AS "_exists"
   FROM "target"
   WHERE "test_valid_from" <= CAST('2020-01-01 00:00:00' AS TIMESTAMP)
@@ -1661,7 +1661,7 @@ def test_merge_scd_type_2_pandas(make_mocked_engine_adapter: t.Callable):
     "price",
     "test_updated_at",
     "test_valid_from",
-    NULL AS "test_valid_to",
+    CAST(NULL AS TIMESTAMPTZ) AS "test_valid_to",
     TRUE AS "_exists"
     FROM "target"
     WHERE "test_valid_from" <= CAST('2020-01-01 00:00:00+00:00' AS TIMESTAMPTZ)
@@ -1839,7 +1839,7 @@ def test_scd_type_2_by_column(make_mocked_engine_adapter: t.Callable):
     "name",
     "price",
     "test_VALID_from",
-    NULL AS "test_valid_to",
+    CAST(NULL AS TIMESTAMP) AS "test_valid_to",
     TRUE AS "_exists"
     FROM "target"
     WHERE "test_VALID_from" <= CAST('2020-01-01 00:00:00' AS TIMESTAMP)
@@ -2034,7 +2034,7 @@ def test_scd_type_2_by_column_composite_key(make_mocked_engine_adapter: t.Callab
     "name",
     "price",
     "test_VALID_from",
-    NULL AS "test_valid_to",
+    CAST(NULL AS TIMESTAMP) AS "test_valid_to",
     TRUE AS "_exists"
     FROM "target"
     WHERE "test_VALID_from" <= CAST('2020-01-01 00:00:00' AS TIMESTAMP)
@@ -2394,7 +2394,7 @@ def test_scd_type_2_by_column_star_check(make_mocked_engine_adapter: t.Callable)
     "name",
     "price",
     "test_valid_from",
-    NULL AS "test_valid_to",
+    CAST(NULL AS TIMESTAMP) AS "test_valid_to",
     TRUE AS "_exists"
     FROM "target"
     WHERE "test_valid_from" <= CAST('2020-01-01 00:00:00' AS TIMESTAMP)
@@ -2570,7 +2570,7 @@ def test_scd_type_2_by_column_no_invalidate_hard_deletes(make_mocked_engine_adap
     "name",
     "price",
     "test_valid_from",
-    NULL AS "test_valid_to",
+    CAST(NULL AS TIMESTAMP) AS "test_valid_to",
     TRUE AS "_exists"
   FROM "target"
   WHERE "test_valid_from" <= CAST('2020-01-01 00:00:00' AS TIMESTAMP)