Dupport quarter in postgres last day (#333)

CHANGELOG.md

@@ -5,11 +5,13 @@
 * Add new schema test, `not_accepted_values` ([#284](https://github.com/fishtown-analytics/dbt-utils/pull/284) [@JavierMonton](https://github.com/JavierMonton))
 * Support a new argument, `zero_length_range_allowed` in the `mutually_exclusive_ranges` test ([#307](https://github.com/fishtown-analytics/dbt-utils/pull/307) [@zemekeng](https://github.com/zemekeneng))
 * Add new schema test, `sequential_values` ([#318](https://github.com/fishtown-analytics/dbt-utils/pull/318), inspired by [@hundredwatt](https://github.com/hundredwatt))
+* Support `quarter` in the `postgres__last_day` macro ([#333](https://github.com/fishtown-analytics/dbt-utils/pull/333/files), [@seunghanhong](https://github.com/seunghanhong))
 
 
 ## 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))
+
 ## Under the hood
 
 

integration_tests/data/cross_db/data_last_day.csv

@@ -1,4 +1,5 @@
 date_day,date_part,result
 2018-01-02,month,2018-01-31
+2018-01-02,quarter,2018-03-31
 2018-01-02,year,2018-12-31
 ,month,

integration_tests/models/cross_db_utils/test_last_day.sql

@@ -8,6 +8,7 @@ with data as (
 select
     case
         when date_part = 'month' then {{ dbt_utils.last_day('date_day', 'month') }}
+        when date_part = 'quarter' then {{ dbt_utils.last_day('date_day', 'quarter') }}
         when date_part = 'year' then {{ dbt_utils.last_day('date_day', 'year') }}
         else null
     end as actual,

macros/cross_db_utils/last_day.sql

@@ -25,8 +25,12 @@ testing is required to validate that it will work on other dateparts.
 {% macro postgres__last_day(date, datepart) -%}
 
     {%- if datepart == 'quarter' -%}
-    {{ exceptions.raise_compiler_error(
-        "dbt_utils.last_day is not supported for datepart 'quarter' on this adapter") }}
+    -- postgres dateadd does not support quarter interval.
+    cast(
+        {{dbt_utils.dateadd('day', '-1',
+        dbt_utils.dateadd('month', '3', dbt_utils.date_trunc(datepart, date))
+        )}}
+        as date)
     {%- else -%}
     {{dbt_utils.default_last_day(date, datepart)}}
     {%- endif -%}