Don't select lastrowid for inline=True

- Fixed bug where SQL Server dialects would attempt to select the
last row identity for an INSERT from SELECT, failing in the case when
the SELECT has no rows.  For such a statement,
the inline flag is set to True indicating no last primary key
should be fetched.

Change-Id: Ic40d56d9eadadc3024a4d71245f9eed4c420024a
Fixes: #3876

3 files changed, 61 insertions, 1 deletions

diff --git a/doc/build/changelog/changelog_11.rst b/doc/build/changelog/changelog_11.rst
index 6b842ab07..8ac241889 100644
--- a/doc/build/changelog/changelog_11.rst
+++ b/doc/build/changelog/changelog_11.rst
@@ -27,6 +27,15 @@
 
         Fixed bug where an INSERT from SELECT where the source table contains
         an autoincrementing Sequence would fail to compile correctly.
+    .. change:: 3876
+        :tags: bug, mssql
+        :tickets: 3876
+
+        Fixed bug where SQL Server dialects would attempt to select the
+        last row identity for an INSERT from SELECT, failing in the case when
+        the SELECT has no rows.  For such a statement,
+        the inline flag is set to True indicating no last primary key
+        should be fetched.
 
     .. change:: 3875
         :tags: bug, oracle
diff --git a/lib/sqlalchemy/dialects/mssql/base.py b/lib/sqlalchemy/dialects/mssql/base.py
index 19558a2d6..1a1f7f06d 100644
--- a/lib/sqlalchemy/dialects/mssql/base.py
+++ b/lib/sqlalchemy/dialects/mssql/base.py
@@ -1022,7 +1022,8 @@ class MSExecutionContext(default.DefaultExecutionContext):
             else:
                 self._enable_identity_insert = False
 
-            self._select_lastrowid = insert_has_sequence and \
+            self._select_lastrowid = not self.compiled.inline and \
+                insert_has_sequence and \
                 not self.compiled.returning and \
                 not self._enable_identity_insert and \
                 not self.executemany
diff --git a/lib/sqlalchemy/testing/suite/test_insert.py b/lib/sqlalchemy/testing/suite/test_insert.py
index 70e8a6b17..c0b6b18eb 100644
--- a/lib/sqlalchemy/testing/suite/test_insert.py
+++ b/lib/sqlalchemy/testing/suite/test_insert.py
@@ -141,6 +141,56 @@ class InsertBehaviorTest(fixtures.TablesTest):
         assert len(r.fetchall())
 
     @requirements.insert_from_select
+    def test_insert_from_select_autoinc(self):
+        src_table = self.tables.manual_pk
+        dest_table = self.tables.autoinc_pk
+        config.db.execute(
+            src_table.insert(),
+            [
+                dict(id=1, data="data1"),
+                dict(id=2, data="data2"),
+                dict(id=3, data="data3"),
+            ]
+        )
+
+        result = config.db.execute(
+            dest_table.insert().
+            from_select(
+                ("data",),
+                select([src_table.c.data]).
+                where(src_table.c.data.in_(["data2", "data3"]))
+            )
+        )
+
+        eq_(result.inserted_primary_key, [None])
+
+        result = config.db.execute(
+            select([dest_table.c.data]).order_by(dest_table.c.data)
+        )
+        eq_(result.fetchall(), [("data2", ), ("data3", )])
+
+    @requirements.insert_from_select
+    def test_insert_from_select_autoinc_no_rows(self):
+        src_table = self.tables.manual_pk
+        dest_table = self.tables.autoinc_pk
+
+        result = config.db.execute(
+            dest_table.insert().
+            from_select(
+                ("data",),
+                select([src_table.c.data]).
+                where(src_table.c.data.in_(["data2", "data3"]))
+            )
+        )
+        eq_(result.inserted_primary_key, [None])
+
+        result = config.db.execute(
+            select([dest_table.c.data]).order_by(dest_table.c.data)
+        )
+
+        eq_(result.fetchall(), [])
+
+    @requirements.insert_from_select
     def test_insert_from_select(self):
         table = self.tables.manual_pk
         config.db.execute(