Add relation type to get_relations_by_pattern and get_relations_by_prefix

[clrcrl]

This is a:

• bug fix PR with no breaking changes — please ensure the base branch is master
• new functionality — please ensure the base branch is the latest dev/ branch (🚨 I created this against master since it's such a tiny change)
• a breaking change — please ensure the base branch is the latest dev/ branch

Description & motivation

I was trying to use this macro today like so:

{% macro cleanup_ci_relations(safe_mode=true) %}
{% set relations_to_drop = dbt_utils.get_relations_by_pattern(
    schema_pattern='my_schema',
    table_pattern='dbt\_%'
) %}

{% set sql_to_execute = [] %}

{% for relation in relations_to_drop %}
    {% set drop_command %}
    drop {{ relation.type }} {{ relation }} cascade;
    {% endset %}
    {% do log(drop_command, info=True) %}
    {% do sql_to_execute.append(drop_command) %}
{% endfor %}

{% endmacro %}

However this line didn't work:

    drop {{ relation.type }} {{ relation }} cascade;

Since relation.type compiled to None.

This fixes the issue, but I'm curious whether there's a smarter thing we should be doing here!

I also took the opportunity to update the docs to hint people towards using the more flexible get_relations_by_pattern (partially by listing it first)

Checklist

• 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 have updated the README.md (if applicable)
• n/a I have added tests & descriptions to my models (and macros if applicable)
• I have added an entry to CHANGELOG.md

[jtcohen6]

I really like it!

This fixes the issue, but I'm curious whether there's a smarter thing we should be doing here!

These macros look more and more like dbt's built-in methods for building the relational cache at the start of an invocations. A cool way to rewrite these could be as regex-y cache lookups—if the dbs/schemas of interest overlap with the ones that dbt knows about—but that's a project for a later day.

Let's merge this in and cut v0.6.4 later today, yeah?