- The INSERT...FROM SELECT construct now implies ``inline=True``

on :class:`.Insert`.  This helps to fix a bug where an
INSERT...FROM SELECT construct would inadvertently be compiled
as "implicit returning" on supporting backends, which would
cause breakage in the case of an INSERT that inserts zero rows
(as implicit returning expects a row), as well as arbitrary
return data in the case of an INSERT that inserts multiple
rows (e.g. only the first row of many).
A similar change is also applied to an INSERT..VALUES
with multiple parameter sets; implicit RETURNING will no longer emit
for this statement either.  As both of these constructs deal
with varible numbers of rows, the
:attr:`.ResultProxy.inserted_primary_key` accessor does not
apply.   Previously, there was a documentation note that one
may prefer ``inline=True`` with INSERT..FROM SELECT as some databases
don't support returning and therefore can't do "implicit" returning,
but there's no reason an INSERT...FROM SELECT needs implicit returning
in any case.   Regular explicit :meth:`.Insert.returning` should
be used to return variable numbers of result rows if inserted
data is needed.
fixes #3169

1 files changed, 107 insertions, 2 deletions

diff --git a/test/sql/test_insert.py b/test/sql/test_insert.py
index d59d79d89..d2fba5862 100644
--- a/test/sql/test_insert.py
+++ b/test/sql/test_insert.py
@@ -17,7 +17,7 @@ class _InsertTestBase(object):
               Column('name', String(30)),
               Column('description', String(30)))
         Table('myothertable', metadata,
-              Column('otherid', Integer),
+              Column('otherid', Integer, primary_key=True),
               Column('othername', String(30)))
 
 
@@ -138,6 +138,23 @@ class InsertTest(_InsertTestBase, fixtures.TablesTest, AssertsCompiledSQL):
             dialect=default.DefaultDialect()
         )
 
+    def test_insert_from_select_returning(self):
+        table1 = self.tables.mytable
+        sel = select([table1.c.myid, table1.c.name]).where(
+            table1.c.name == 'foo')
+        ins = self.tables.myothertable.insert().\
+            from_select(("otherid", "othername"), sel).returning(
+                self.tables.myothertable.c.otherid
+            )
+        self.assert_compile(
+            ins,
+            "INSERT INTO myothertable (otherid, othername) "
+            "SELECT mytable.myid, mytable.name FROM mytable "
+            "WHERE mytable.name = %(name_1)s RETURNING myothertable.otherid",
+            checkparams={"name_1": "foo"},
+            dialect="postgresql"
+        )
+
     def test_insert_from_select_select(self):
         table1 = self.tables.mytable
         sel = select([table1.c.myid, table1.c.name]).where(
@@ -230,7 +247,7 @@ class InsertTest(_InsertTestBase, fixtures.TablesTest, AssertsCompiledSQL):
         )
         ins = mytable.insert().\
             from_select(
-            [mytable.c.name, mytable.c.description], sel)
+                [mytable.c.name, mytable.c.description], sel)
         self.assert_compile(
             ins,
             "INSERT INTO mytable (name, description) "
@@ -254,6 +271,94 @@ class InsertTest(_InsertTestBase, fixtures.TablesTest, AssertsCompiledSQL):
         )
 
 
+class InsertImplicitReturningTest(
+        _InsertTestBase, fixtures.TablesTest, AssertsCompiledSQL):
+    __dialect__ = postgresql.dialect(implicit_returning=True)
+
+    def test_insert_select(self):
+        table1 = self.tables.mytable
+        sel = select([table1.c.myid, table1.c.name]).where(
+            table1.c.name == 'foo')
+        ins = self.tables.myothertable.insert().\
+            from_select(("otherid", "othername"), sel)
+        self.assert_compile(
+            ins,
+            "INSERT INTO myothertable (otherid, othername) "
+            "SELECT mytable.myid, mytable.name FROM mytable "
+            "WHERE mytable.name = %(name_1)s",
+            checkparams={"name_1": "foo"}
+        )
+
+    def test_insert_select_return_defaults(self):
+        table1 = self.tables.mytable
+        sel = select([table1.c.myid, table1.c.name]).where(
+            table1.c.name == 'foo')
+        ins = self.tables.myothertable.insert().\
+            from_select(("otherid", "othername"), sel).\
+            return_defaults(self.tables.myothertable.c.otherid)
+        self.assert_compile(
+            ins,
+            "INSERT INTO myothertable (otherid, othername) "
+            "SELECT mytable.myid, mytable.name FROM mytable "
+            "WHERE mytable.name = %(name_1)s",
+            checkparams={"name_1": "foo"}
+        )
+
+    def test_insert_multiple_values(self):
+        ins = self.tables.myothertable.insert().values([
+            {"othername": "foo"},
+            {"othername": "bar"},
+        ])
+        self.assert_compile(
+            ins,
+            "INSERT INTO myothertable (othername) "
+            "VALUES (%(othername_0)s), "
+            "(%(othername_1)s)",
+            checkparams={
+                'othername_1': 'bar',
+                'othername_0': 'foo'}
+        )
+
+    def test_insert_multiple_values_return_defaults(self):
+        # TODO: not sure if this should raise an
+        # error or what
+        ins = self.tables.myothertable.insert().values([
+            {"othername": "foo"},
+            {"othername": "bar"},
+        ]).return_defaults(self.tables.myothertable.c.otherid)
+        self.assert_compile(
+            ins,
+            "INSERT INTO myothertable (othername) "
+            "VALUES (%(othername_0)s), "
+            "(%(othername_1)s)",
+            checkparams={
+                'othername_1': 'bar',
+                'othername_0': 'foo'}
+        )
+
+    def test_insert_single_list_values(self):
+        ins = self.tables.myothertable.insert().values([
+            {"othername": "foo"},
+        ])
+        self.assert_compile(
+            ins,
+            "INSERT INTO myothertable (othername) "
+            "VALUES (%(othername_0)s)",
+            checkparams={'othername_0': 'foo'}
+        )
+
+    def test_insert_single_element_values(self):
+        ins = self.tables.myothertable.insert().values(
+            {"othername": "foo"},
+        )
+        self.assert_compile(
+            ins,
+            "INSERT INTO myothertable (othername) "
+            "VALUES (%(othername)s) RETURNING myothertable.otherid",
+            checkparams={'othername': 'foo'}
+        )
+
+
 class EmptyTest(_InsertTestBase, fixtures.TablesTest, AssertsCompiledSQL):
     __dialect__ = 'default'