fix: source_column_name none

[kmclaugh]

source_column_name need a none test not "!="

resolves #

This is a:

• documentation update
• [* ] bug fix with no breaking changes
• new functionality
• a breaking change

All pull requests from community contributors should target the main branch (default).

Description & motivation

Fix source_column_name check in union_relations

Checklist

• This code is associated with an Issue which has been triaged and accepted for development.
• I have verified that these changes work locally on the following warehouses (Note: it's okay if you do not have access to all warehouses, this helps us understand what has been covered)
  • [*] BigQuery
  • Postgres
  • Redshift
  • Snowflake
• I followed guidelines to ensure that my changes will work on "non-core" adapters by:
  • dispatching any new macro(s) so non-core adapters can also use them (e.g. the star() source)
  • using the limit_zero() macro in place of the literal string: limit 0
  • using dbt.type_* macros instead of explicit datatypes (e.g. dbt.type_timestamp() instead of TIMESTAMP
• I have updated the README.md (if applicable)
• I have added tests & descriptions to my models (and macros if applicable)
• [*] I have added an entry to CHANGELOG.md

[joellabes]

Good catch! Thanks @kmclaugh

[smitsrr]

Was this put into a dbt_utils release?

[joellabes]

@smitsrr yep! It went out in https://github.com/dbt-labs/dbt-utils/releases/tag/0.9.2 (but I just saw that the GH release notes weren't clear about this so have clarified them)