Fix cardinality test error (#334)

Author: Joel Labes

CHANGELOG.md

@@ -11,10 +11,10 @@
 ## Fixes
 * Handle booleans gracefully in the unpivot macro ([#305](https://github.com/fishtown-analytics/dbt-utils/pull/305) [@avishalom](https://github.com/avishalom))
 * Fix a bug in `get_relation_by_prefix` that happens with Snowflake external tables. Now the macro will retrieve tables that match the prefix which are external tables ([#350](https://github.com/fishtown-analytics/dbt-utils/issues/350))
+* Fix `cardinality_equality` test when the two tables' column names differed ([#334](https://github.com/fishtown-analytics/dbt-utils/pull/334)) [@joellabes](https://github.com/joellabes)
 
 ## Under the hood
 
-
 # dbt-utils v0.6.4
 
 ### Fixes

integration_tests/data/schema_tests/data_cardinality_equality_a.csv

@@ -0,0 +1,4 @@
+same_name
+1
+2
+3

integration_tests/data/schema_tests/data_cardinality_equality_b.csv

@@ -0,0 +1,4 @@
+same_name,different_name
+1,2
+2,3
+3,1

integration_tests/models/schema_tests/schema.yml

@@ -126,6 +126,18 @@ models:
           combination_of_columns:
             - month
             - product
+  
+  - name: data_cardinality_equality_a
+    columns:
+      - name: same_name
+        tests:
+          - dbt_utils.cardinality_equality:
+              to: ref('data_cardinality_equality_b')
+              field: same_name
+          - dbt_utils.cardinality_equality:
+              to: ref('data_cardinality_equality_b')
+              field: different_name
+          
 
   - name: data_test_accepted_range
     columns:
@@ -145,3 +157,4 @@ models:
               min_value: 0
               inclusive: true
               where: "id <> -1"
+

macros/schema_tests/cardinality_equality.sql

@@ -25,7 +25,7 @@ select
   {{ field }},
   count(*) as num_rows
 from {{ to }}
-group by {{ column_name }}
+group by {{ field }}
 ),
 
 except_a as (