Add reflection for Identity columns

Added support for reflecting "identity" columns, which are now returned
as part of the structure returned by :meth:`_reflection.Inspector.get_columns`.
When reflecting full :class:`_schema.Table` objects, identity columns will
be represented using the :class:`_schema.Identity` construct.

Fixed compilation error on oracle for sequence and identity column
``nominvalue`` and ``nomaxvalue`` options that require no space in them.

Improved test compatibility with oracle 18.

As part of the support for reflecting :class:`_schema.Identity` objects,
the method :meth:`_reflection.Inspector.get_columns` no longer returns
``mssql_identity_start`` and ``mssql_identity_increment`` as part of the
``dialect_options``. Use the information in the ``identity`` key instead.

The mssql dialect will assume that at least MSSQL 2005 is used.
There is no hard exception raised if a previous version is detected,
but operations may fail for older versions.

Fixes: #5527
Fixes: #5324
Change-Id: If039fe637c46b424499e6bac54a2cbc0dc54cb57

1 files changed, 8 insertions, 4 deletions

diff --git a/test/sql/test_identity_column.py b/test/sql/test_identity_column.py
index 2564022c2..0b1bffd00 100644
--- a/test/sql/test_identity_column.py
+++ b/test/sql/test_identity_column.py
@@ -57,13 +57,17 @@ class _IdentityDDLFixture(testing.AssertsCompiledSQL):
             dict(always=False, cache=1000, order=True),
             "BY DEFAULT AS IDENTITY (CACHE 1000 ORDER)",
         ),
-        (
-            dict(order=True),
-            "BY DEFAULT AS IDENTITY (ORDER)",
-        ),
+        (dict(order=True), "BY DEFAULT AS IDENTITY (ORDER)"),
     )
     def test_create_ddl(self, identity_args, text):
 
+        if getattr(self, "__dialect__", None) != "default" and testing.against(
+            "oracle"
+        ):
+            text = text.replace("NO MINVALUE", "NOMINVALUE").replace(
+                "NO MAXVALUE", "NOMAXVALUE"
+            )
+
         t = Table(
             "foo_table",
             MetaData(),