Merge pull request dbt-labs#248 from fishtown-analytics/clrcrl/distin…

…ct-pivot

Add distinct argument to pivot macro. fka dbt-labs#213

macros/sql/pivot.sql

@@ -37,6 +37,7 @@ Arguments:
     then_value: Value to use if comparison succeeds, default is 1
     else_value: Value to use if comparison fails, default is 0
     quote_identifiers: Whether to surround column aliases with double quotes, default is true
+    distinct: Whether to use distinct in the aggregation, default is False
 #}
 
 {% macro pivot(column,
@@ -48,9 +49,11 @@ Arguments:
                suffix='',
                then_value=1,
                else_value=0,
-               quote_identifiers=True) %}
+               quote_identifiers=True,
+               distinct=False) %}
   {% for v in values %}
     {{ agg }}(
+      {% if distinct %} distinct {% endif %}
       case
       when {{ column }} {{ cmp }} '{{ v }}'
         then {{ then_value }}