From d2ccc85b3eda7d87f686abad332c0ec84511f001 Mon Sep 17 00:00:00 2001
From: Judah Rand <17158624+judahrand@users.noreply.github.com>
Date: Thu, 14 Apr 2022 11:22:16 +0100
Subject: [PATCH] Use `natural join` to avoid having to parse expressions

---
 macros/sql/deduplicate.sql | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/macros/sql/deduplicate.sql b/macros/sql/deduplicate.sql
index c1c3c29b..9e6ac5a8 100644
--- a/macros/sql/deduplicate.sql
+++ b/macros/sql/deduplicate.sql
@@ -17,18 +17,16 @@
     )
 
     select
-        data.*
+        distinct data.*
     from {{ relation }} as data
-    join row_numbered using (
-        {{ group_by }}
-        {% for expression in order_by.split(',') %}
-        {% if expression.lower().endswith(' asc') or expression.lower().endswith(' desc') %}
-            {{ ',' ~ expression.rsplit(' ', 1)[0] }}
-        {% else %}
-            {{ ',' ~ expression }}
-        {% endif %}
-        {% endfor %}
-    )
+    {#
+    -- Not all DBs will support natural joins but the ones that do include:
+    -- Oracle, MySQL, SQLite, Redshift, Teradata, Materialize, Databricks
+    -- Apache Spark, SingleStore, Vertica
+    -- Those that do not appear to support natural joins include:
+    -- SQLServer, Trino, Presto, Rockset, Athena
+    #}
+    natural join row_numbered
     where row_numbered.rn = 1
 
 {%- endmacro -%}