Update star.sql to allow for non-quote wrapped column names

[CR-Lough]

resolves #644

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

The star.sql macro inside of dbt-utils/sql forces users to encase column names in quotes. This change adds the optional 'quote_identifier' parameter (default True) to the macro.

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

[dbeatty10]

Nice persistence on this @CR-Lough 💪

This one is kinda tricky to test! Let me try to explain why, and a possible path forward.

This PR is enabling new behavior to choose between quoted identifiers (default) and non-quoted identifiers. To me, it seems the best way to test this is by actually examine the string produced by star() and seeing if the value matches the expectations (e.g., starting and ending with the adapter.quote value or not depending on the arguments).

Creating such a test could be a bit different than existing tests. It might look something like this (which I didn't actually try out!):

integration_tests/data/sql/single_column_table.csv

my_column
x

integration_tests/models/sql/test_star_quote_identifiers.sql

select
    {{ dbt.string_literal(adapter.quote("my_column")) | lower }} as expected,
    {{ dbt_utils.star(from=ref('single_column_table', quote_identifiers=True)) | trim | lower }} as actual

union all

select
    {{ dbt.string_literal("my_column") | lower }} as expected,
    {{ dbt_utils.star(from=ref('single_column_table', quote_identifiers=False)) | trim | lower }} as actual

integration_tests/models/sql/schema.yml

  - name: test_star_quote_identifiers
    tests:
      - assert_equal:
          actual: actual
          expected: expected

I put in all the extra lower filters because some databases will return lowercase and others uppercase, and we want the same logic to work across adapters. It could just as easily be upper filters instead.

[dbeatty10]

This looks awesome @CR-Lough -- nice work figuring out those tests 💪

I took another pass through this PR and saw that there's no updates reflecting the new argument within the README.

Could you add your new argument here?

dbt-utils/README.md

Lines 936 to 942 in 6a5dd1e

	**Args:**
	- `from` (required): a [Relation](https://docs.getdbt.com/reference/dbt-classes#relation) (a `ref` or `source`) that contains the list of columns you wish to select from
	- `except` (optional, default=`[]`): The name of the columns you wish to exclude. (case-insensitive)
	- `relation_alias` (optional, default=`''`): will prefix all generated fields with an alias (`relation_alias`.`field_name`).
	- `prefix` (optional, default=`''`): will prefix the output `field_name` (`field_name as prefix_field_name`).
	- `suffix` (optional, default=`''`): will suffix the output `field_name` (`field_name as field_name_suffix`).

And an example usage here?

dbt-utils/README.md

Lines 944 to 965 in 6a5dd1e

	**Usage:**
	```sql
	select
	{{ dbt_utils.star(ref('my_model')) }}
	from {{ ref('my_model') }}
	```
	```sql
	select
	{{ dbt_utils.star(from=ref('my_model'), except=["exclude_field_1", "exclude_field_2"]) }}
	from {{ ref('my_model') }}
	```
	```sql
	select
	{{ dbt_utils.star(from=ref('my_model'), except=["exclude_field_1", "exclude_field_2"], prefix="max_") }}
	from {{ ref('my_model') }}
	```

[CR-Lough]

@dbeatty10 that last addition to the README.md should be the last checkbox in the list of items at the top of the page 👍

[dbeatty10]

@CR-Lough Thanks for this contribution to add the optional configuration to star() for quoting identifiers! 🚀

[dbeatty10]

The first time I read this, I thought it meant quoting the optional relation_alias. But re-reading it, I realize it means the alias it is assigned (if any).