From b36cff765167b368efd6b18ee493e33f216cac14 Mon Sep 17 00:00:00 2001
From: azban <me@azban.net>
Date: Thu, 27 Jul 2023 18:25:47 -0700
Subject: [PATCH] add PARTITION BY option for CopyInto

---
 src/snowflake/sqlalchemy/base.py            | 11 +++++++----
 src/snowflake/sqlalchemy/custom_commands.py | 11 ++++++++---
 tests/test_copy.py                          | 10 ++++++++++
 3 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/src/snowflake/sqlalchemy/base.py b/src/snowflake/sqlalchemy/base.py
index 9835ced2..a47b54a1 100644
--- a/src/snowflake/sqlalchemy/base.py
+++ b/src/snowflake/sqlalchemy/base.py
@@ -215,7 +215,6 @@ def visit_copy_into(self, copy_into, **kw):
             if isinstance(copy_into.into, Table)
             else copy_into.into._compiler_dispatch(self, **kw)
         )
-        from_ = None
         if isinstance(copy_into.from_, Table):
             from_ = copy_into.from_
         # this is intended to catch AWSBucket and AzureContainer
@@ -228,6 +227,11 @@ def visit_copy_into(self, copy_into, **kw):
         # everything else (selects, etc.)
         else:
             from_ = f"({copy_into.from_._compiler_dispatch(self, **kw)})"
+
+        partition_by = ""
+        if copy_into.partition_by is not None:
+            partition_by = f"PARTITION BY {copy_into.partition_by}"
+
         credentials, encryption = "", ""
         if isinstance(into, tuple):
             into, credentials, encryption = into
@@ -238,8 +242,7 @@ def visit_copy_into(self, copy_into, **kw):
             options_list.sort(key=operator.itemgetter(0))
         options = (
             (
-                " "
-                + " ".join(
+                " ".join(
                     [
                         "{} = {}".format(
                             n,
@@ -258,7 +261,7 @@ def visit_copy_into(self, copy_into, **kw):
             options += f" {credentials}"
         if encryption:
             options += f" {encryption}"
-        return f"COPY INTO {into} FROM {from_} {formatter}{options}"
+        return f"COPY INTO {into} FROM {' '.join([from_, partition_by, formatter, options])}"
 
     def visit_copy_formatter(self, formatter, **kw):
         options_list = list(formatter.options.items())
diff --git a/src/snowflake/sqlalchemy/custom_commands.py b/src/snowflake/sqlalchemy/custom_commands.py
index 9bb60916..64ffd2cf 100644
--- a/src/snowflake/sqlalchemy/custom_commands.py
+++ b/src/snowflake/sqlalchemy/custom_commands.py
@@ -114,18 +114,23 @@ class CopyInto(UpdateBase):
     __visit_name__ = "copy_into"
     _bind = None
 
-    def __init__(self, from_, into, formatter=None):
+    def __init__(self, from_, into, partition_by=None, formatter=None):
         self.from_ = from_
         self.into = into
         self.formatter = formatter
         self.copy_options = {}
+        self.partition_by = partition_by
 
     def __repr__(self):
         """
         repr for debugging / logging purposes only. For compilation logic, see
         the corresponding visitor in base.py
         """
-        return f"COPY INTO {self.into} FROM {repr(self.from_)} {repr(self.formatter)} ({self.copy_options})"
+        val = f"COPY INTO {self.into} FROM {repr(self.from_)}"
+        if self.partition_by is not None:
+            val += f" PARTITION BY {self.partition_by}"
+
+        return val + f" {repr(self.formatter)} ({self.copy_options})"
 
     def bind(self):
         return None
@@ -530,7 +535,7 @@ def __repr__(self):
         )
 
     def credentials(
-        self, aws_role=None, aws_key_id=None, aws_secret_key=None, aws_token=None
+            self, aws_role=None, aws_key_id=None, aws_secret_key=None, aws_token=None
     ):
         if aws_role is None and (aws_key_id is None and aws_secret_key is None):
             raise ValueError(
diff --git a/tests/test_copy.py b/tests/test_copy.py
index e0752d4f..92e38160 100644
--- a/tests/test_copy.py
+++ b/tests/test_copy.py
@@ -151,6 +151,16 @@ def test_copy_into_location(engine_testaccount, sql_compiler):
         == "COPY INTO @name.stage_name/prefix/file FROM python_tests_foods FILE_FORMAT=(TYPE=csv)"
     )
 
+    copy_stmt_7 = CopyIntoStorage(
+        from_=food_items,
+        into=ExternalStage(name="stage_name"),
+        partition_by="('YEAR=' || year)"
+    )
+    assert (
+        sql_compiler(copy_stmt_7)
+        == "COPY INTO @stage_name FROM python_tests_foods PARTITION BY ('YEAR=' || year)"
+    )
+
     # NOTE Other than expect known compiled text, submit it to RegressionTests environment and expect them to fail, but
     # because of the right reasons
     acceptable_exc_reasons = {