pass optional sql_header to empty subquery sql rendering (dbt-labs#7734)

.changes/unreleased/Fixes-20230531-131919.yaml

@@ -0,0 +1,6 @@
+kind: Fixes
+body: send sql header on contract enforcement
+time: 2023-05-31T13:19:19.801391-04:00
+custom:
+ Author: michelleark
+ Issue: "7714"

core/dbt/include/global_project/macros/adapters/columns.sql

@@ -17,15 +17,18 @@
 {% endmacro %}
 
 
-{% macro get_empty_subquery_sql(select_sql) -%}
- {{ return(adapter.dispatch('get_empty_subquery_sql', 'dbt')(select_sql)) }}
+{% macro get_empty_subquery_sql(select_sql, select_sql_header=none) -%}
+ {{ return(adapter.dispatch('get_empty_subquery_sql', 'dbt')(select_sql, select_sql_header)) }}
 {% endmacro %}
 
 {#
  Builds a query that results in the same schema as the given select_sql statement, without necessitating a data scan.
  Useful for running a query in a 'pre-flight' context, such as model contract enforcement (assert_columns_equivalent macro).
 #}
-{% macro default__get_empty_subquery_sql(select_sql) %}
+{% macro default__get_empty_subquery_sql(select_sql, select_sql_header=none) %}
+ {%- if select_sql_header is not none -%}
+ {{ select_sql_header }}
+ {%- endif -%}
  select * from (
  {{ select_sql }}
  ) as __dbt_sbq
@@ -53,10 +56,10 @@
  {%- endif -%}
 {% endmacro %}
 
-{% macro get_column_schema_from_query(select_sql) -%}
+{% macro get_column_schema_from_query(select_sql, select_sql_header=none) -%}
  {% set columns = [] %}
  {# -- Using an 'empty subquery' here to get the same schema as the given select_sql statement, without necessitating a data scan.#}
- {% set sql = get_empty_subquery_sql(select_sql) %}
+ {% set sql = get_empty_subquery_sql(select_sql, select_sql_header) %}
  {% set column_schema = adapter.get_column_schema_from_query(sql) %}
  {{ return(column_schema) }}
 {% endmacro %}

core/dbt/include/global_project/macros/materializations/models/table/columns_spec_ddl.sql

@@ -34,7 +34,7 @@
 #}
 {% macro assert_columns_equivalent(sql) %}
  {#-- Obtain the column schema provided by sql file. #}
- {%- set sql_file_provided_columns = get_column_schema_from_query(sql) -%}
+ {%- set sql_file_provided_columns = get_column_schema_from_query(sql, config.get('sql_header', none)) -%}
  {#--Obtain the column schema provided by the schema file by generating an 'empty schema' query from the model's columns. #}
  {%- set schema_file_provided_columns = get_column_schema_from_query(get_empty_schema_sql(model['columns'])) -%}
 

tests/adapter/dbt/tests/adapter/constraints/fixtures.py

@@ -133,6 +133,33 @@
  {sql_value} as wrong_data_type_column_name
 """
 
+my_model_contract_sql_header_sql = """
+{{
+ config(
+ materialized = "table"
+ )
+}}
+
+{% call set_sql_header(config) %}
+set session time zone 'Asia/Kolkata';
+{%- endcall %}
+select current_setting('timezone') as column_name
+"""
+
+my_model_incremental_contract_sql_header_sql = """
+{{
+ config(
+ materialized = "incremental",
+ on_schema_change="append_new_columns"
+ )
+}}
+
+{% call set_sql_header(config) %}
+set session time zone 'Asia/Kolkata';
+{%- endcall %}
+select current_setting('timezone') as column_name
+"""
+
 # model breaking constraints
 my_model_with_nulls_sql = """
 {{
@@ -303,3 +330,15 @@
  - name: wrong_data_type_column_name
  data_type: {data_type}
 """
+
+model_contract_header_schema_yml = """
+version: 2
+models:
+ - name: my_model_contract_sql_header
+ config:
+ contract:
+ enforced: true
+ columns:
+ - name: column_name
+ data_type: text
+"""

tests/adapter/dbt/tests/adapter/constraints/test_constraints.py

@@ -25,6 +25,9 @@
  my_model_incremental_with_nulls_sql,
  model_schema_yml,
  constrained_model_schema_yml,
+ my_model_contract_sql_header_sql,
+ my_model_incremental_contract_sql_header_sql,
+ model_contract_header_schema_yml,
 )
 
 
@@ -358,6 +361,45 @@ class TestIncrementalConstraintsRollback(BaseIncrementalConstraintsRollback):
  pass
 
 
+class BaseContractSqlHeader:
+ """Tests a contracted model with a sql header dependency."""
+
+ def test__contract_sql_header(self, project):
+ run_dbt(["run", "-s", "my_model_contract_sql_header"])
+
+ manifest = get_manifest(project.project_root)
+ model_id = "model.test.my_model_contract_sql_header"
+ model_config = manifest.nodes[model_id].config
+
+ assert model_config.contract.enforced
+
+
+class BaseTableContractSqlHeader(BaseContractSqlHeader):
+ @pytest.fixture(scope="class")
+ def models(self):
+ return {
+ "my_model_contract_sql_header.sql": my_model_contract_sql_header_sql,
+ "constraints_schema.yml": model_contract_header_schema_yml,
+ }
+
+
+class BaseIncrementalContractSqlHeader(BaseContractSqlHeader):
+ @pytest.fixture(scope="class")
+ def models(self):
+ return {
+ "my_model_contract_sql_header.sql": my_model_incremental_contract_sql_header_sql,
+ "constraints_schema.yml": model_contract_header_schema_yml,
+ }
+
+
+class TestTableContractSqlHeader(BaseTableContractSqlHeader):
+ pass
+
+
+class TestIncrementalContractSqlHeader(BaseIncrementalContractSqlHeader):
+ pass
+
+
 class BaseModelConstraintsRuntimeEnforcement:
  """
  These model-level constraints pass muster for dbt's preflight checks. Make sure they're