Revert automatic set of sequence start to 1

The :class:`.Sequence` construct restores itself to the DDL behavior it
had prior to the 1.4 series, where creating a :class:`.Sequence` with
no additional arguments will emit a simple ``CREATE SEQUENCE`` instruction
**without** any additional parameters for "start value".   For most backends,
this is how things worked previously in any case; **however**, for
MS SQL Server, the default value on this database is
``-2**63``; to prevent this generally impractical default
from taking effect on SQL Server, the :paramref:`.Sequence.start` parameter
should be provided.   As usage of :class:`.Sequence` is unusual
for SQL Server which for many years has standardized on ``IDENTITY``,
it is hoped that this change has minimal impact.

Fixes: #7211
Change-Id: I1207ea10c8cb1528a1519a0fb3581d9621c27b31

3 files changed, 20 insertions, 8 deletions

diff --git a/test/engine/test_ddlevents.py b/test/engine/test_ddlevents.py
index 1b57895dc..1fa17c889 100644
--- a/test/engine/test_ddlevents.py
+++ b/test/engine/test_ddlevents.py
@@ -18,9 +18,11 @@ from sqlalchemy.schema import DropConstraint
 from sqlalchemy.schema import ForeignKeyConstraint
 from sqlalchemy.schema import Sequence
 from sqlalchemy.testing import AssertsCompiledSQL
+from sqlalchemy.testing import config
 from sqlalchemy.testing import engines
 from sqlalchemy.testing import eq_
 from sqlalchemy.testing import fixtures
+from sqlalchemy.testing.provision import normalize_sequence
 from sqlalchemy.testing.schema import Column
 from sqlalchemy.testing.schema import Table
 
@@ -542,7 +544,7 @@ class SequenceDDLEventTest(DDLEventWCreateHarness, fixtures.TestBase):
 
     @testing.fixture
     def produce_subject(self):
-        return Sequence("my_seq")
+        return normalize_sequence(config, Sequence("my_seq"))
 
     @testing.fixture
     def produce_table_integrated_subject(self, metadata, produce_subject):
diff --git a/test/engine/test_execute.py b/test/engine/test_execute.py
index 2940a1e7f..c1fe3140e 100644
--- a/test/engine/test_execute.py
+++ b/test/engine/test_execute.py
@@ -53,6 +53,7 @@ from sqlalchemy.testing import is_false
 from sqlalchemy.testing import is_not
 from sqlalchemy.testing import is_true
 from sqlalchemy.testing.assertsql import CompiledSQL
+from sqlalchemy.testing.provision import normalize_sequence
 from sqlalchemy.testing.schema import Column
 from sqlalchemy.testing.schema import Table
 from sqlalchemy.testing.util import gc_collect
@@ -1222,7 +1223,7 @@ class MockStrategyTest(fixtures.TestBase):
             Column(
                 "pk",
                 Integer,
-                Sequence("testtable_pk_seq"),
+                normalize_sequence(config, Sequence("testtable_pk_seq")),
                 primary_key=True,
             ),
         )
@@ -2408,7 +2409,7 @@ class EngineEventsTest(fixtures.TestBase):
             Column(
                 "x",
                 Integer,
-                Sequence("t_id_seq"),
+                normalize_sequence(config, Sequence("t_id_seq")),
                 primary_key=True,
             ),
             implicit_returning=False,
diff --git a/test/engine/test_reflection.py b/test/engine/test_reflection.py
index 7c5672066..2aefecaef 100644
--- a/test/engine/test_reflection.py
+++ b/test/engine/test_reflection.py
@@ -38,6 +38,7 @@ from sqlalchemy.testing import is_true
 from sqlalchemy.testing import mock
 from sqlalchemy.testing import not_in
 from sqlalchemy.testing import skip
+from sqlalchemy.testing.provision import normalize_sequence
 from sqlalchemy.testing.schema import Column
 from sqlalchemy.testing.schema import Table
 
@@ -1391,7 +1392,9 @@ class CreateDropTest(fixtures.TablesTest):
             Column(
                 "user_id",
                 sa.Integer,
-                sa.Sequence("user_id_seq", optional=True),
+                normalize_sequence(
+                    config, sa.Sequence("user_id_seq", optional=True)
+                ),
                 primary_key=True,
             ),
             Column("user_name", sa.String(40)),
@@ -1403,7 +1406,9 @@ class CreateDropTest(fixtures.TablesTest):
             Column(
                 "address_id",
                 sa.Integer,
-                sa.Sequence("address_id_seq", optional=True),
+                normalize_sequence(
+                    config, sa.Sequence("address_id_seq", optional=True)
+                ),
                 primary_key=True,
             ),
             Column("user_id", sa.Integer, sa.ForeignKey("users.user_id")),
@@ -1416,7 +1421,9 @@ class CreateDropTest(fixtures.TablesTest):
             Column(
                 "order_id",
                 sa.Integer,
-                sa.Sequence("order_id_seq", optional=True),
+                normalize_sequence(
+                    config, sa.Sequence("order_id_seq", optional=True)
+                ),
                 primary_key=True,
             ),
             Column("user_id", sa.Integer, sa.ForeignKey("users.user_id")),
@@ -1429,7 +1436,9 @@ class CreateDropTest(fixtures.TablesTest):
             Column(
                 "item_id",
                 sa.INT,
-                sa.Sequence("items_id_seq", optional=True),
+                normalize_sequence(
+                    config, sa.Sequence("items_id_seq", optional=True)
+                ),
                 primary_key=True,
             ),
             Column("order_id", sa.INT, sa.ForeignKey("orders")),
@@ -1597,7 +1606,7 @@ class UnicodeReflectionTest(fixtures.TablesTest):
                 Column(
                     "id",
                     sa.Integer,
-                    sa.Sequence(cname + "_id_seq"),
+                    normalize_sequence(config, sa.Sequence(cname + "_id_seq")),
                     primary_key=True,
                 ),
                 Column(cname, Integer),