Allow aliasing individual columns from star macro.

dbt-labs · elliottohara · Jun 10, 2020 · Jun 10, 2020 · f22eac843486b065c26e0917b413e76968d11e67 · elliottohara
commit f22eac843486b065c26e0917b413e76968d11e67
diff --git a/README.md b/README.md
@@ -446,11 +446,11 @@ Usage:
 
 #### star ([source](macros/sql/star.sql))
 This macro generates a list of all fields that exist in the `from` relation, excluding any fields listed in the `except` argument. The construction is identical to `select * from {{ref('my_model')}}`, replacing star (`*`) with the star macro. This macro also has an optional `relation_alias` argument that will prefix all generated fields with an alias.
-
+It also has an optional arg that allows aliasing of individual columns.
 Usage:
 ```
 select
-{{ dbt_utils.star(from=ref('my_model'), except=["exclude_field_1", "exclude_field_2"]) }}
+{{ dbt_utils.star(from=ref('my_model'), except=["exclude_field_1", "exclude_field_2"], aliases={"field_x":"pretty_name", "field_y":"another_pretty_name"}) }}
 from {{ref('my_model')}}
 ```
 

diff --git a/integration_tests/data/sql/data_star_aliases_expected.csv b/integration_tests/data/sql/data_star_aliases_expected.csv
@@ -0,0 +1,4 @@
+field_1,field_2,aliased
+a,b,c
+d,e,f
+g,h,i
diff --git a/integration_tests/dbt_project.yml b/integration_tests/dbt_project.yml
@@ -2,6 +2,7 @@
 name: 'dbt_utils_integration_tests'
 version: '1.0'
 
+
 profile: 'integration_tests'
 
 require-dbt-version: ">=0.15.1"

diff --git a/integration_tests/models/sql/schema.yml b/integration_tests/models/sql/schema.yml
@@ -101,6 +101,11 @@ models:
       - dbt_utils.equality:
           compare_model: ref('data_star_expected')
 
+  - name: test_star_aliases
+    tests:
+      - dbt_utils.equality:
+          compare_model: ref('data_star_aliases_expected')
+
   - name: test_surrogate_key
     tests:
       - assert_equal:

diff --git a/integration_tests/models/sql/test_star_aliases.sql b/integration_tests/models/sql/test_star_aliases.sql
@@ -0,0 +1,16 @@
+
+-- TODO : Should the star macro use a case-insensitive comparison for the `except` field on Snowflake?
+
+{% set aliases = {'FIELD_3':'aliased'} if target.type == 'snowflake' else {'field_3':'aliased'} %}
+
+
+with data as (
+
+    select
+        {{ dbt_utils.star(from=ref('data_star'), aliases=aliases) }}
+
+    from {{ ref('data_star') }}
+
+)
+
+select * from data
diff --git a/macros/sql/star.sql b/macros/sql/star.sql
@@ -1,4 +1,4 @@
-{% macro star(from, relation_alias=False, except=[]) -%}
+{% macro star(from, relation_alias=False, except=[], aliases={}) -%}
 
     {%- do dbt_utils._is_relation(from, 'star') -%}
 
@@ -19,7 +19,7 @@
 
     {%- for col in include_cols %}
 
-        {%- if relation_alias %}{{ relation_alias }}.{% else %}{%- endif -%}{{ adapter.quote(col)|trim }}
+        {%- if relation_alias %}{{ relation_alias }}.{% else %}{%- endif -%}{{ adapter.quote(col)|trim }}{%- if col in aliases %} as {{ adapter.quote(aliases[col]) | trim }}{%- endif -%}
         {%- if not loop.last %},{{ '\n  ' }}{% endif %}
 
     {%- endfor -%}