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

5 files changed, 32 insertions, 1 deletions

diff --git a/doc/build/changelog/unreleased_14/5506.rst b/doc/build/changelog/unreleased_14/5506.rst
index 71b57322d..1614efeca 100644
--- a/doc/build/changelog/unreleased_14/5506.rst
+++ b/doc/build/changelog/unreleased_14/5506.rst
@@ -1,5 +1,5 @@
 .. change::
-    :tags: usecase, mssql
+    :tags: usecase, mssql, reflection
     :tickets: 5506
 
     Added support for reflection of temporary tables with the SQL Server dialect.
diff --git a/doc/build/changelog/unreleased_14/5527.rst b/doc/build/changelog/unreleased_14/5527.rst
new file mode 100644
index 000000000..e6721df12
--- /dev/null
+++ b/doc/build/changelog/unreleased_14/5527.rst
@@ -0,0 +1,11 @@
+.. change::
+    :tags: sql, reflection
+    :tickets: 5527, 5324
+
+    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.
+    Currently the supported backends are
+    PostgreSQL >= 10, Oracle >= 12 and MSSQL (with different syntax
+    and a subset of functionalities).
diff --git a/doc/build/changelog/unreleased_14/mssql_identity_dialect_options.rst b/doc/build/changelog/unreleased_14/mssql_identity_dialect_options.rst
new file mode 100644
index 000000000..8676c7d25
--- /dev/null
+++ b/doc/build/changelog/unreleased_14/mssql_identity_dialect_options.rst
@@ -0,0 +1,8 @@
+.. change::
+    :tags: mssql, reflection
+    :tickets: 5527
+
+    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.
diff --git a/doc/build/changelog/unreleased_14/mssql_version.rst b/doc/build/changelog/unreleased_14/mssql_version.rst
new file mode 100644
index 000000000..9454cc45a
--- /dev/null
+++ b/doc/build/changelog/unreleased_14/mssql_version.rst
@@ -0,0 +1,6 @@
+.. change::
+    :tags: mssql
+
+    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.
diff --git a/doc/build/changelog/unreleased_14/oracle_sequence_options.rst b/doc/build/changelog/unreleased_14/oracle_sequence_options.rst
new file mode 100644
index 000000000..738958d0c
--- /dev/null
+++ b/doc/build/changelog/unreleased_14/oracle_sequence_options.rst
@@ -0,0 +1,6 @@
+.. change::
+    :tags: oracle, bug
+
+    Correctly render :class:`_schema.Sequence` and :class:`_schema.Identity`
+    column options ``nominvalue`` and ``nomaxvalue`` as ``NOMAXVALUE` and
+    ``NOMINVALUE`` on oracle database.