Add unload macro example

macros/snowflake/unloading.sql

@@ -0,0 +1,39 @@
+{% macro create_unload_external_stage() %}
+    {% if env_var('DBT_ENVIRONMENT', 'dev') == 'prod' %}
+        {% set sql %}
+            CREATE OR REPLACE STAGE dbt_ext_unload_stage
+                url='s3://your-company-artifacts/snowflake-unload/dbt/'
+                credentials=(aws_key_id='{{ env_var('DBT_SECRET_AWS_ACCESS_KEY_ID') }}', aws_secret_key='{{ env_var('DBT_SECRET_AWS_SECRET_ACCESS_KEY') }}')
+                file_format = (type = csv, field_optionally_enclosed_by = '"', compression = gzip);
+        {% endset %}
+        {% set _ = run_query(sql) %}
+    {% endif %}
+{% endmacro %}
+
+{% macro unload_to_s3() %}
+    -- Another example here:  https://gist.github.com/jeremyyeo/f07dbe9a7687ffc4976e1488a8e35547
+
+    {% if env_var('DBT_ENVIRONMENT', 'dev') == 'prod' %}
+
+        {% set sql %}
+
+        -- Unload (possibly multiple) data files into timestamped directory.
+        COPY INTO @dbt_ext_unload_stage/{{ this.name }}/{{ run_started_at.date().isoformat() }}/{{ run_started_at.isoformat() }}/data
+        FROM {{ this }}
+        header = true;
+
+        -- Add an indicator that the unload has completed.
+        COPY INTO @dbt_ext_unload_stage/{{ this.name }}/{{ run_started_at.date().isoformat() }}/{{ run_started_at.isoformat() }}/done.csv
+        FROM (SELECT 1 AS done)
+        single = true;
+
+        {% endset %}
+
+        {% if execute %}
+
+            {% do run_query(sql) %}
+
+        {% endif %}
+
+    {% endif %}
+{% endmacro %}