Adds 3 parameters to unpivot: remove, field_name, value_name

README.md

@@ -337,7 +337,7 @@ This macro "un-pivots" a table from wide format to long format. Functionality is
 
 Usage:
 ```
-{{ dbt_utils.unpivot(table=ref('table_name'), cast_to='datatype', exclude=[<list of columns to exclude from unpivot>]) }}
+{{ dbt_utils.unpivot(table=ref('table_name'), cast_to='datatype', exclude=[<list of columns to exclude from unpivot>], remove=[<list of columns to remove>], field_name=<column name for field>, value_name=<column name for value>) }}
 ```
 
 Example:
@@ -364,7 +364,10 @@ Arguments:
 
     - table: Table name, required
     - cast_to: The data type to cast the unpivoted values to, default is varchar
-    - exclude: A list of columns to exclude from the unpivot.
+    - exclude: A list of columns to exclude from the unpivot operation but keep in the resulting table.
+    - 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
 
 ---
 ### Web

integration_tests/data/sql/data_unpivot.csv

@@ -1,4 +1,4 @@
-customer_id,created_at,status,segment
-123,2017-01-01,active,tier 1
-234,2017-02-01,active,tier 3
-567,2017-03-01,churned,tier 2
+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_expected.csv

@@ -1,7 +1,10 @@
-customer_id,created_at,field_name,value
-123,2017-01-01,status,active
-123,2017-01-01,segment,tier 1
-234,2017-02-01,status,active
-234,2017-02-01,segment,tier 3
-567,2017-03-01,status,churned
-567,2017-03-01,segment,tier 2
+customer_id,created_at,prop,val
+123,"2017-01-01","segment","tier 1"
+123,"2017-01-01","status","active"
+123,"2017-01-01","name","name 1"
+234,"2017-02-01","segment","tier 3"
+234,"2017-02-01","status","active"
+234,"2017-02-01","name","name 3"
+567,"2017-03-01","status","churned"
+567,"2017-03-01","name","name 2"
+567,"2017-03-01","segment","tier 2"

integration_tests/data/sql/data_unpivot_original_api_expected.csv

@@ -0,0 +1,10 @@
+customer_id,created_at,field_name,value
+123,2017-01-01,status,active
+123,2017-01-01,segment,tier 1
+234,2017-02-01,status,active
+234,2017-02-01,segment,tier 3
+567,2017-03-01,status,churned
+567,2017-03-01,segment,tier 2
+123,2017-01-01,name,name 1
+234,2017-02-01,name,name 3
+567,2017-03-01,name,name 2

integration_tests/models/sql/schema.yml

@@ -5,51 +5,51 @@ models:
     tests:
       - dbt_utils.equality:
           arg: ref('data_generate_series')
-        
+
   - name: test_get_column_values
     columns:
       - name: count_a
         tests:
           - accepted_values:
               values:
                 - '1'
-            
+
       - name: count_b
         tests:
           - accepted_values:
               values:
                 - '1'
-            
+
       - name: count_c
         tests:
           - accepted_values:
               values:
                 - '1'
-            
+
       - name: count_d
         tests:
           - accepted_values:
               values:
                 - '1'
-            
+
       - name: count_e
         tests:
           - accepted_values:
               values:
                 - '1'
-            
+
       - name: count_f
         tests:
           - accepted_values:
               values:
                 - '1'
-            
+
       - name: count_g
         tests:
           - accepted_values:
               values:
                 - '5'
-          
+
   - name: test_get_tables_by_prefix_and_union
     columns:
       - name: event
@@ -60,42 +60,47 @@ models:
           - dbt_utils.at_least_one
           - not_null
           - unique
-      
+
   - name: test_nullcheck_table
     columns:
       - name: field_1
         tests:
           - not_empty_string
-      
+
       - name: field_2
         tests:
           - not_empty_string
-      
+
       - name: field_3
         tests:
           - not_empty_string
-      
+
   - name: test_pivot
     tests:
       - dbt_utils.equality:
           compare_model: ref('data_pivot_expected')
-
+
+  - name: test_unpivot_original_api
+    tests:
+      - dbt_utils.equality:
+          compare_model: ref('data_unpivot_original_api_expected')
+
   - name: test_unpivot
     tests:
       - dbt_utils.equality:
           compare_model: ref('data_unpivot_expected')
-        
+
   - name: test_star
     tests:
       - dbt_utils.equality:
           compare_model: ref('data_star_expected')
-          
+
   - name: test_surrogate_key
     tests:
       - assert_equal:
           actual: actual
           expected: expected
-        
+
   - name: test_union
     tests:
       - dbt_utils.equality:

integration_tests/models/sql/test_unpivot.sql

@@ -11,19 +11,23 @@
     {% set exclude = ['customer_id', 'created_at'] %}
 {% endif %}
 
+
 select
     customer_id,
     created_at,
     case
-        when '{{ target.name }}' = 'snowflake' then lower(field_name)
-        else field_name
-    end as field_name,
-    value
+        when '{{ target.name }}' = 'snowflake' then lower(prop)
+        else prop
+    end as prop,
+    val
 
 from (
     {{ dbt_utils.unpivot(
         table=ref('data_unpivot'),
         cast_to=dbt_utils.type_string(),
-        exclude=exclude
+        exclude=exclude,
+        remove='name',
+        field_name='prop',
+        value_name='val'
     ) }}
 ) as sbq

integration_tests/models/sql/test_unpivot_original_api.sql

@@ -0,0 +1,32 @@
+
+-- unpivot() was enhanced with 3 new parameters
+-- This test targets the original API.
+
+-- snowflake messes with these tests pretty badly since the
+-- output of the macro considers the casing of the source
+-- table columns. Using some hacks here to get this to work,
+-- but we should consider lowercasing the unpivot macro output
+-- at some point in the future for consistency
+
+{% if target.name == 'snowflake' %}
+    {% set exclude = ['CUSTOMER_ID', 'CREATED_AT'] %}
+{% else %}
+    {% set exclude = ['customer_id', 'created_at'] %}
+{% endif %}
+
+select
+    customer_id,
+    created_at,
+    case
+        when '{{ target.name }}' = 'snowflake' then lower(FIELD_NAME)
+        else field_name
+    end as field_name,
+    value
+
+from (
+    {{ dbt_utils.unpivot(
+        table=ref('data_unpivot'),
+        cast_to=dbt_utils.type_string(),
+        exclude=exclude
+    ) }}
+) as sbq

macros/sql/unpivot.sql

@@ -1,17 +1,21 @@
 {#
-Pivot values from columns to rows.
+Pivot values from columns to rows. Similar to pandas DataFrame melt() function.
 
-Example Usage: {{ dbt_utils.unpivot(table=ref('users'), cast_to='integer', exclude=['id','created_at']) }}
+Example Usage: {{ unpivot(table=ref('users'), cast_to='integer', exclude=['id','created_at']) }}
 
 Arguments:
     table: Relation object, required.
     cast_to: The datatype to cast all unpivoted columns to. Default is varchar.
-    exclude: A list of columns to exclude from the unpivot operation. Default is none.
+    exclude: A list of columns to keep but exclude from the unpivot operation. Default is none.
+    remove: A list of columns to remove from the resulting table. Default is none.
+    field_name: Destination table column name for the source table column names.
+    value_name: Destination table column name for the pivoted values
 #}
 
-{% macro unpivot(table, cast_to='varchar', exclude=none) -%}
+{% macro unpivot(table, cast_to='varchar', exclude=none, remove=none, field_name='field_name', value_name='value') -%}
 
   {%- set exclude = exclude if exclude is not none else [] %}
+  {%- set remove = remove if remove is not none else [] %}
 
   {%- set include_cols = [] %}
 
@@ -23,22 +27,26 @@ Arguments:
   {%- set cols = adapter.get_columns_in_relation(table) %}
 
   {%- for col in cols -%}
-    {%- if col.column.lower() not in exclude|map('lower') -%}
+    {%- if col.column.lower() not in remove|map('lower') and col.column.lower() not in exclude|map('lower') -%}
       {% set _ = include_cols.append(col) %}
     {%- endif %}
   {%- endfor %}
 
-  {%- for col in include_cols -%}
 
+  {%- for col in include_cols -%}
     select
       {%- for exclude_col in exclude %}
         {{ exclude_col }},
       {%- endfor %}
-      cast('{{ col.column }}' as {{ dbt_utils.type_string() }}) as field_name,
-      cast({{ col.column }} as {{ cast_to }}) as value
+
+      cast('{{ col.column }}' as {{ dbt_utils.type_string() }}) as {{ field_name }},
+      cast({{ col.column }} as {{ cast_to }}) as {{ value_name }}
+
     from {{ table }}
+
     {% if not loop.last -%}
       union all
     {% endif -%}
   {%- endfor -%}
+
 {%- endmacro %}