Add column tag support for views (#1134)

Author: ericj-db

CHANGELOG.md

@@ -1,5 +1,8 @@
 ## dbt-databricks 1.10.9 (TBD)
 
+### Features
+- Support column tags for views using `ALTER TABLE`
+
 ## dbt-databricks 1.10.8 (August 4, 2025)
 
 ### Features

dbt/adapters/databricks/relation_configs/view.py

@@ -8,6 +8,7 @@
     DatabricksRelationConfigBase,
 )
 from dbt.adapters.databricks.relation_configs.column_comments import ColumnCommentsProcessor
+from dbt.adapters.databricks.relation_configs.column_tags import ColumnTagsProcessor
 from dbt.adapters.databricks.relation_configs.comment import CommentProcessor
 from dbt.adapters.databricks.relation_configs.query import QueryProcessor
 from dbt.adapters.databricks.relation_configs.tags import TagsProcessor
@@ -21,6 +22,7 @@ class ViewConfig(DatabricksRelationConfigBase):
         QueryProcessor,
         CommentProcessor,
         ColumnCommentsProcessor,
+        ColumnTagsProcessor,
     ]
 
     def get_changeset(self, existing: Self) -> Optional[DatabricksRelationChangeSet]:

dbt/include/databricks/macros/materializations/view.sql

@@ -31,6 +31,10 @@
         {{ get_create_view_as_sql(target_relation, sql) }}
       {%- endcall %}
       {{ apply_tags(target_relation, tags) }}
+      {% set column_tags = adapter.get_column_tags_from_model(config.model) %}
+      {% if column_tags and column_tags.set_column_tags %}
+        {{ apply_column_tags(target_relation, column_tags) }}
+      {% endif %}
     {% endif %}
     {% set should_revoke = should_revoke(exists_as_view, full_refresh_mode=True) %}
     {% do apply_grants(target_relation, grant_config, should_revoke=True) %}
@@ -57,6 +61,11 @@
 
     {%- do apply_tags(target_relation, tags) -%}
 
+    {% set column_tags = adapter.get_column_tags_from_model(config.model) %}
+    {% if column_tags and column_tags.set_column_tags %}
+      {{ apply_column_tags(target_relation, column_tags) }}
+    {% endif %}
+
     {{ run_hooks(post_hooks) }}
   {% endif %}
 
@@ -69,6 +78,11 @@
   {% set tags = config.get('databricks_tags') %}
   {{ execute_multiple_statements(get_replace_sql(existing_relation, target_relation, sql)) }}
   {%- do apply_tags(target_relation, tags) -%}
+  
+  {% set column_tags = adapter.get_column_tags_from_model(config.model) %}
+  {% if column_tags and column_tags.set_column_tags %}
+    {{ apply_column_tags(target_relation, column_tags) }}
+  {% endif %}
 {% endmacro %}
 
 {% macro relation_should_be_altered(existing_relation) %}

dbt/include/databricks/macros/relations/components/column_tags.sql

@@ -34,7 +34,12 @@
 {%- endmacro -%}
 
 {% macro alter_set_column_tags(relation, column, tags) -%}
-  ALTER {{ relation.type | replace('_', ' ') }} {{ relation.render() }}
+  {# ALTER VIEW does not support setting column tags, but ALTER TABLE works for views #}
+  {%- if relation.type == 'view' -%}
+    ALTER TABLE {{ relation.render() }}
+  {%- else -%}
+    ALTER {{ relation.type | replace('_', ' ') }} {{ relation.render() }}
+  {%- endif -%}
   ALTER COLUMN `{{ column }}`
   SET TAGS (
     {%- for tag_name, tag_value in tags.items() -%}

dbt/include/databricks/macros/relations/view/create.sql

@@ -2,9 +2,6 @@
   {% if column_mask_exists() %}
     {% do exceptions.raise_compiler_error("Column masks are not supported for views.") %}
   {% endif %}
-  {% if column_tags_exist() %}
-    {% do exceptions.raise_compiler_error("Column tags are not supported for views.") %}
-  {% endif %}
   {{ log("Creating view " ~ relation) }}
   create or replace view {{ relation.render() }}
   {%- if config.persist_column_docs() -%}

tests/functional/adapter/column_tags/fixtures.py

@@ -2,7 +2,7 @@
 select 1 as id, 'abc123' as account_number
 """
 
-model_with_column_tags = """
+initial_column_tag_model = """
 version: 2
 models:
   - name: base_model
@@ -16,6 +16,22 @@
           sensitive: "true"
 """
 
+updated_column_tag_model = """
+version: 2
+models:
+  - name: base_model
+    config:
+        materialized: table
+    columns:
+      - name: id
+        databricks_tags:
+          pii: "false"
+      - name: account_number
+        databricks_tags:
+          pii: "true"
+          sensitive: "true"
+"""
+
 column_tags_seed = """
 id,account_number
 1,'1234567890'

tests/functional/adapter/column_tags/test_column_tags.py

@@ -6,67 +6,76 @@
 
 
 class ColumnTagsMixin(MaterializationV2Mixin):
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "base_model.sql": fixtures.base_model_sql,
+            "schema.yml": fixtures.initial_column_tag_model.replace(
+                "materialized: table", f"materialized: {self.relation_type}"
+            ),
+        }
+
     def test_column_tags(self, project):
         util.run_dbt(["run"])
 
-        # Check that column tags were applied
-        tags = project.run_sql(
-            f"""
+        column_tags_query = f"""
             SELECT column_name, tag_name, tag_value
             FROM `system`.`information_schema`.`column_tags`
             WHERE catalog_name = '{project.database}'
               AND schema_name = '{project.test_schema}'
               AND table_name = 'base_model'
             ORDER BY column_name, tag_name
-            """,
-            fetch="all",
-        )
+            """
 
+        # Check that column tags were applied
+        tags = project.run_sql(column_tags_query, fetch="all")
         expected_tags = {
             ("account_number", "pii", "true"),
             ("account_number", "sensitive", "true"),
         }
+        actual_tags = {(row[0], row[1], row[2]) for row in tags}
+        assert actual_tags == expected_tags
 
+        # Run a second time with an updated model
+        util.write_file(
+            fixtures.updated_column_tag_model.replace(
+                "materialized: table", f"materialized: {self.relation_type}"
+            ),
+            "models",
+            "schema.yml",
+        )
+        util.run_dbt(["run"])
+
+        # Check that column tags were updated
+        tags = project.run_sql(column_tags_query, fetch="all")
+        expected_tags = {
+            ("id", "pii", "false"),
+            ("account_number", "pii", "true"),
+            ("account_number", "sensitive", "true"),
+        }
         actual_tags = {(row[0], row[1], row[2]) for row in tags}
         assert actual_tags == expected_tags
 
 
 @pytest.mark.skip_profile("databricks_cluster")
 class TestColumnTagsTable(ColumnTagsMixin):
-    @pytest.fixture(scope="class")
-    def models(self):
-        return {
-            "base_model.sql": fixtures.base_model_sql,
-            "schema.yml": fixtures.model_with_column_tags,
-        }
+    relation_type = "table"
 
 
 @pytest.mark.skip_profile("databricks_cluster")
 class TestColumnTagsIncremental(ColumnTagsMixin):
-    @pytest.fixture(scope="class")
-    def models(self):
-        return {
-            "base_model.sql": fixtures.base_model_sql,
-            "schema.yml": fixtures.model_with_column_tags.replace(
-                "materialized: table", "materialized: incremental"
-            ),
-        }
+    relation_type = "incremental"
 
 
 @pytest.mark.skip_profile("databricks_cluster", "databricks_uc_cluster")
 class TestColumnTagsMaterializedView(ColumnTagsMixin):
-    @pytest.fixture(scope="class")
-    def models(self):
-        return {
-            "base_model.sql": fixtures.base_model_sql,
-            "schema.yml": fixtures.model_with_column_tags.replace(
-                "materialized: table", "materialized: materialized_view"
-            ),
-        }
+    relation_type = "materialized_view"
 
 
 @pytest.mark.skip_profile("databricks_cluster", "databricks_uc_cluster")
 class TestStreamingTableColumnTags(ColumnTagsMixin):
+    relation_type = "streaming_table"
+
     @pytest.fixture(scope="class")
     def seeds(self):
         return {
@@ -77,7 +86,7 @@ def seeds(self):
     def models(self):
         return {
             "base_model.sql": fixtures.base_model_streaming_table,
-            "schema.yml": fixtures.model_with_column_tags.replace(
+            "schema.yml": fixtures.initial_column_tag_model.replace(
                 "materialized: table", "materialized: streaming_table"
             ),
         }
@@ -88,16 +97,5 @@ def setup_streaming_table_seed(self, project):
 
 
 @pytest.mark.skip_profile("databricks_cluster")
-class TestViewColumnTagsFailure(MaterializationV2Mixin):
-    @pytest.fixture(scope="class")
-    def models(self):
-        return {
-            "base_model.sql": fixtures.base_model_sql,
-            "schema.yml": fixtures.model_with_column_tags.replace(
-                "materialized: table", "materialized: view"
-            ),
-        }
-
-    def test_view_column_tags_failure(self, project):
-        result = util.run_dbt(["run"], expect_pass=False)
-        assert "Column tags are not supported" in result.results[0].message
+class TestColumnTagsView(ColumnTagsMixin):
+    relation_type = "view"