From b39bc68ab788d38eb2141e3b16f947e8159bdd5e Mon Sep 17 00:00:00 2001
From: Gord Thompson <gord@gordthompson.com>
Date: Tue, 31 Dec 2019 12:42:09 -0500
Subject: [PATCH] Fix DATETIMEOFFSET formatting to preserve fractional seconds.

Fixed issue where a timezone-aware ``datetime`` value being converted to
string for use as a parameter value of a :class:`.mssql.DATETIMEOFFSET`
column was omitting the fractional seconds.

Fixes: #5045
Closes: #5046
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/5046
Pull-request-sha: 99dc7b23f69b7b068795a02d20b88bf352c7dcd7

Change-Id: I971629466fe0675536bbdf55693f0c1821dfb3cc
(cherry picked from commit 0d316e42f0645283c222f050c403c9c8d20463ec)
---
 doc/build/changelog/unreleased_13/5045.rst | 7 +++++++
 lib/sqlalchemy/dialects/mssql/pyodbc.py    | 4 ++--
 test/dialect/mssql/test_types.py           | 2 +-
 3 files changed, 10 insertions(+), 3 deletions(-)
 create mode 100644 doc/build/changelog/unreleased_13/5045.rst

diff --git a/doc/build/changelog/unreleased_13/5045.rst b/doc/build/changelog/unreleased_13/5045.rst
new file mode 100644
index 0000000000..020e723a06
--- /dev/null
+++ b/doc/build/changelog/unreleased_13/5045.rst
@@ -0,0 +1,7 @@
+.. change::
+    :tags: bug, mssql
+    :tickets: 5045
+
+    Fixed issue where a timezone-aware ``datetime`` value being converted to
+    string for use as a parameter value of a :class:`.mssql.DATETIMEOFFSET`
+    column was omitting the fractional seconds.
diff --git a/lib/sqlalchemy/dialects/mssql/pyodbc.py b/lib/sqlalchemy/dialects/mssql/pyodbc.py
index 9ce6861c06..c3304a7055 100644
--- a/lib/sqlalchemy/dialects/mssql/pyodbc.py
+++ b/lib/sqlalchemy/dialects/mssql/pyodbc.py
@@ -235,9 +235,9 @@ class _ODBCDateTimeOffset(DATETIMEOFFSET):
     def bind_processor(self, dialect):
         def process(value):
             """Convert to string format required by T-SQL."""
-            dto_string = value.strftime("%Y-%m-%d %H:%M:%S %z")
+            dto_string = value.strftime("%Y-%m-%d %H:%M:%S.%f %z")
             # offset needs a colon, e.g., -0700 -> -07:00
-            return dto_string[:23] + ":" + dto_string[23:]
+            return dto_string[:30] + ":" + dto_string[30:]
 
         return process
 
diff --git a/test/dialect/mssql/test_types.py b/test/dialect/mssql/test_types.py
index f837d3add0..3cf9d9036d 100644
--- a/test/dialect/mssql/test_types.py
+++ b/test/dialect/mssql/test_types.py
@@ -735,7 +735,7 @@ class TypeRoundTripTest(
             11,
             2,
             32,
-            0,
+            123456,
             util.timezone(datetime.timedelta(hours=1)),
         )
         t.insert().execute(
-- 
2.47.2