[Backport 1.6.latest] Fix #8022: Foreign key constraint on incrementa…

…l model results in Database Error (#8808)

(cherry picked from commit 6461f5a)

Co-authored-by: Kshitij Aranke <kshitij.aranke@dbtlabs.com>

.changes/unreleased/Fixes-20231004-154558.yaml

@@ -0,0 +1,6 @@
+kind: Fixes
+body: Foreign key constraint on incremental model results in Database Error
+time: 2023-10-04T15:45:58.298548+01:00
+custom:
+ Author: aranke
+ Issue: "8022"

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

@@ -26,7 +26,7 @@
  create {% if temporary: -%}temporary{%- endif %} table
  {{ relation.include(database=(not temporary), schema=(not temporary)) }}
  {% set contract_config = config.get('contract') %}
- {% if contract_config.enforced %}
+ {% if contract_config.enforced and (not temporary) %}
  {{ get_assert_columns_equivalent(sql) }}
  {{ get_table_columns_and_constraints() }}
  {%- set sql = get_select_subquery(sql) %}

plugins/postgres/dbt/include/postgres/macros/adapters.sql

@@ -10,7 +10,7 @@
  unlogged
  {%- endif %} table {{ relation }}
  {% set contract_config = config.get('contract') %}
- {% if contract_config.enforced %}
+ {% if contract_config.enforced and (not temporary) %}
  {{ get_assert_columns_equivalent(sql) }}
  {{ get_table_columns_and_constraints() }} ;
  insert into {{ relation }} (

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

@@ -539,3 +539,47 @@
  - name: column_name
  data_type: text
 """
+
+create_table_macro_sql = """
+{% macro create_table_macro() %}
+create table if not exists numbers (n int not null primary key)
+{% endmacro %}
+"""
+
+incremental_foreign_key_schema_yml = """
+version: 2
+
+models:
+ - name: raw_numbers
+ config:
+ contract:
+ enforced: true
+ materialized: table
+ columns:
+ - name: n
+ data_type: integer
+ constraints:
+ - type: primary_key
+ - type: not_null
+ - name: stg_numbers
+ config:
+ contract:
+ enforced: true
+ materialized: incremental
+ on_schema_change: append_new_columns
+ unique_key: n
+ columns:
+ - name: n
+ data_type: integer
+ constraints:
+ - type: foreign_key
+ expression: {schema}.raw_numbers (n)
+"""
+
+incremental_foreign_key_model_raw_numbers_sql = """
+select 1 as n
+"""
+
+incremental_foreign_key_model_stg_numbers_sql = """
+select * from {{ ref('raw_numbers') }}
+"""

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

@@ -34,6 +34,10 @@
  my_model_contract_sql_header_sql,
  my_model_incremental_contract_sql_header_sql,
  model_contract_header_schema_yml,
+ create_table_macro_sql,
+ incremental_foreign_key_schema_yml,
+ incremental_foreign_key_model_raw_numbers_sql,
+ incremental_foreign_key_model_stg_numbers_sql,
 )
 
 
@@ -530,3 +534,31 @@ def expected_sql(self):
 
 class TestConstraintQuotedColumn(BaseConstraintQuotedColumn):
  pass
+
+
+class TestIncrementalForeignKeyConstraint:
+ @pytest.fixture(scope="class")
+ def macros(self):
+ return {
+ "create_table.sql": create_table_macro_sql,
+ }
+
+ @pytest.fixture(scope="class")
+ def models(self):
+ return {
+ "schema.yml": incremental_foreign_key_schema_yml,
+ "raw_numbers.sql": incremental_foreign_key_model_raw_numbers_sql,
+ "stg_numbers.sql": incremental_foreign_key_model_stg_numbers_sql,
+ }
+
+ def test_incremental_foreign_key_constraint(self, project):
+ unformatted_constraint_schema_yml = read_file("models", "schema.yml")
+ write_file(
+ unformatted_constraint_schema_yml.format(schema=project.test_schema),
+ "models",
+ "schema.yml",
+ )
+
+ run_dbt(["run", "--select", "raw_numbers"])
+ run_dbt(["run", "--select", "stg_numbers"])
+ run_dbt(["run", "--select", "stg_numbers"])