Add quote_identifiers parameter to unpivot to handle case-sensiti…

…ve column names (#792)

* feat(unpivot): add quote identifier parameter to unpivot macro

fixes #216

* Changelog will be updated as part of release process

* Enable test for unpivoting quoted columns for Redshift

* Fix warning related to `tests:` -> `data_tests:`

* Simplify the case-sensitive unpivot test model

* Add a newline for consistency

* Use mixed-case column names for all columns

---------

Co-authored-by: Doug Beatty <doug.beatty@dbtlabs.com>

README.md

@@ -1228,6 +1228,7 @@ Boolean values are replaced with the strings 'true'|'false'
 - `remove`: A list of columns to remove from the resulting table.
 - `field_name`: column name in the resulting table for field
 - `value_name`: column name in the resulting table for value
+- `quote_identifiers` (optional, default=`False`): will encase selected columns and aliases in quotes according to your adapter's implementation of `adapter.quote` (e.g. `"field_name" as "field_name"`).
 
 ### width_bucket ([source](macros/sql/width_bucket.sql))
 

integration_tests/data/sql/data_unpivot_quote.csv

@@ -0,0 +1,4 @@
+Customer_Id,Created_At,sTaTuS,SEGMENT,Name
+123,2017-01-01,active,tier 1,name 1
+234,2017-02-01,active,tier 3,name 3
+567,2017-03-01,churned,tier 2,name 2

integration_tests/data/sql/data_unpivot_quote_expected.csv

@@ -0,0 +1,7 @@
+Customer_Id,Created_At,Prop,Val
+123,"2017-01-01","SEGMENT","tier 1"
+123,"2017-01-01","sTaTuS","active"
+234,"2017-02-01","SEGMENT","tier 3"
+234,"2017-02-01","sTaTuS","active"
+567,"2017-03-01","sTaTuS","churned"
+567,"2017-03-01","SEGMENT","tier 2"

integration_tests/dbt_project.yml

@@ -52,6 +52,12 @@ seeds:
           num_buckets: integer
           min_value: float
           max_value: float
+
+      data_unpivot_quote:
+        +quote_columns: true
+
+      data_unpivot_quote_expected:
+        +quote_columns: true
 
     schema_tests:
       data_test_sequential_timestamps:

integration_tests/models/sql/schema.yml

@@ -158,6 +158,11 @@ models:
       - dbt_utils.equality:
           compare_model: ref('data_unpivot_bool_expected')
 
+  - name: test_unpivot_quote
+    data_tests:
+      - dbt_utils.equality:
+          compare_model: ref('data_unpivot_quote_expected')
+
   - name: test_star
     data_tests:
       - dbt_utils.equality:

integration_tests/models/sql/test_unpivot_quote.sql

@@ -0,0 +1,10 @@
+
+    {{ dbt_utils.unpivot(
+        relation=ref('data_unpivot_quote'),
+        cast_to=type_string(),
+        exclude=['Customer_Id', 'Created_At'],
+        remove=['Name'],
+        field_name='Prop',
+        value_name='Val',
+        quote_identifiers=True,
+    ) }}

macros/sql/unpivot.sql

@@ -12,11 +12,11 @@ Arguments:
     value_name: Destination table column name for the pivoted values
 #}
 
-{% macro unpivot(relation=none, cast_to='varchar', exclude=none, remove=none, field_name='field_name', value_name='value') -%}
-    {{ return(adapter.dispatch('unpivot', 'dbt_utils')(relation, cast_to, exclude, remove, field_name, value_name)) }}
+{% macro unpivot(relation=none, cast_to='varchar', exclude=none, remove=none, field_name='field_name', value_name='value', quote_identifiers=False) -%}
+    {{ return(adapter.dispatch('unpivot', 'dbt_utils')(relation, cast_to, exclude, remove, field_name, value_name, quote_identifiers)) }}
 {% endmacro %}
 
-{% macro default__unpivot(relation=none, cast_to='varchar', exclude=none, remove=none, field_name='field_name', value_name='value') -%}
+{% macro default__unpivot(relation=none, cast_to='varchar', exclude=none, remove=none, field_name='field_name', value_name='value', quote_identifiers=False) -%}
 
     {% if not relation %}
         {{ exceptions.raise_compiler_error("Error: argument `relation` is required for `unpivot` macro.") }}
@@ -43,18 +43,19 @@ Arguments:
 
 
   {%- for col in include_cols -%}
+    {%- set current_col_name = adapter.quote(col.column) if quote_identifiers else col.column -%}
     select
       {%- for exclude_col in exclude %}
-        {{ exclude_col }},
+        {{ adapter.quote(exclude_col) if quote_identifiers else exclude_col }},
       {%- endfor %}
 
-      cast('{{ col.column }}' as {{ dbt.type_string() }}) as {{ field_name }},
+      cast('{{ col.column }}' as {{ dbt.type_string() }}) as {{ adapter.quote(field_name) if quote_identifiers else field_name  }},
       cast(  {% if col.data_type == 'boolean' %}
-           {{ dbt.cast_bool_to_text(col.column) }}
+           {{ dbt.cast_bool_to_text(current_col_name) }}
              {% else %}
-           {{ col.column }}
+           {{ current_col_name }}
              {% endif %}
-           as {{ cast_to }}) as {{ value_name }}
+           as {{ cast_to }}) as {{ adapter.quote(value_name) if quote_identifiers else value_name }}
 
     from {{ relation }}