Contract not respect query_settings

[alexsubota]

Bug: Contract validation fails when join_use_nulls is configured via query_settings

Description

When join_use_nulls=1 is configured through query_settings in a model config, dbt contract validation incorrectly fails for a nullable column.

The same model passes contract validation when join_use_nulls is specified directly in the query instead.

Reproduction

my_model.sql

{{
    config(
        order_by='id',
        query_settings={
            'join_use_nulls': 1
        }
    )
}}

select
    id,
    last_value
from (
    select 1 as id
) t1
left join (
    select
        1 as id,
        max(value) as last_value
    from (
        select 1 as value
    )
    where value = 2
) t2
    on t1.id = t2.id

my_model.yml

models:
  - name: my_model
    config:
      contract:
        enforced: true
    columns:
      - name: id
        data_type: UInt8
      - name: last_value
        data_type: Nullable(UInt8)

Expected behavior

Contract validation should succeed because last_value is returned as Nullable(UInt8) when join_use_nulls=1 is enabled.

Actual behavior

Contract validation fails due to a type mismatch.

Additional information

If join_use_nulls is specified directly in the model query instead of through query_settings, contract validation succeeds.

Environment

• dbt version: 1.10.19
• dbt-clickhouse version: 1.10.0
• ClickHouse version: 25.4

[ashoksmore]

Hi @alexsubota, I'd like to work on this.

Looks like contract validation's schema introspection path doesn't apply model query_settings (similar to #441 / PR #278 for other contract paths).
Plan: pass query_settings through get_column_schema_from_query and add an integration test with your repro.

Happy to take this if no one else is already on it.

[koletzilla]

Hi!

Thanks for reporting it. @ashoksmore I think you're in a good direction with this:

Plan: pass query_settings through get_column_schema_from_query and add an integration test with your repro.

Feel free to work on it! I think we need to also add the query_settings inside the adapter's check_incremental_schema_changes method. Could you also take a look at it? Thanks!