Support local timespamp support on Oracle

Added support for the Oracle SQL type ``TIMESTAMP WITH LOCAL TIME ZONE``,
using a newly added Oracle-specific :class:`_oracle.TIMESTAMP` datatype.

Fixes: #9086
Change-Id: Ib14119503a8aaf20e1aa4e36be80ccca37383e90

2 files changed, 35 insertions, 2 deletions

diff --git a/lib/sqlalchemy/dialects/oracle/base.py b/lib/sqlalchemy/dialects/oracle/base.py
index d24df7ee0..65377be28 100644
--- a/lib/sqlalchemy/dialects/oracle/base.py
+++ b/lib/sqlalchemy/dialects/oracle/base.py
@@ -564,6 +564,7 @@ from .types import NVARCHAR2  # noqa
 from .types import OracleRaw  # noqa
 from .types import RAW
 from .types import ROWID  # noqa
+from .types import TIMESTAMP
 from .types import VARCHAR2  # noqa
 from ... import Computed
 from ... import exc
@@ -595,7 +596,6 @@ from ...types import INTEGER
 from ...types import NCHAR
 from ...types import NVARCHAR
 from ...types import REAL
-from ...types import TIMESTAMP
 from ...types import VARCHAR
 
 RESERVED_WORDS = set(
@@ -635,6 +635,7 @@ ischema_names = {
     "NCLOB": NCLOB,
     "TIMESTAMP": TIMESTAMP,
     "TIMESTAMP WITH TIME ZONE": TIMESTAMP,
+    "TIMESTAMP WITH LOCAL TIME ZONE": TIMESTAMP,
     "INTERVAL DAY TO SECOND": INTERVAL,
     "RAW": RAW,
     "FLOAT": FLOAT,
@@ -681,7 +682,9 @@ class OracleTypeCompiler(compiler.GenericTypeCompiler):
         return "LONG"
 
     def visit_TIMESTAMP(self, type_, **kw):
-        if type_.timezone:
+        if getattr(type_, "local_timezone", False):
+            return "TIMESTAMP WITH LOCAL TIME ZONE"
+        elif type_.timezone:
             return "TIMESTAMP WITH TIME ZONE"
         else:
             return "TIMESTAMP"
@@ -2330,6 +2333,8 @@ class OracleDialect(default.DefaultDialect):
                 coltype = self.ischema_names.get(coltype)(char_length)
             elif "WITH TIME ZONE" in coltype:
                 coltype = TIMESTAMP(timezone=True)
+            elif "WITH LOCAL TIME ZONE" in coltype:
+                coltype = TIMESTAMP(local_timezone=True)
             else:
                 coltype = re.sub(r"\(\d+\)", "", coltype)
                 try:
diff --git a/lib/sqlalchemy/dialects/oracle/types.py b/lib/sqlalchemy/dialects/oracle/types.py
index af66d2eb4..db3d57228 100644
--- a/lib/sqlalchemy/dialects/oracle/types.py
+++ b/lib/sqlalchemy/dialects/oracle/types.py
@@ -5,6 +5,7 @@
 # the MIT License: https://www.opensource.org/licenses/mit-license.php
 # mypy: ignore-errors
 
+from ... import exc
 from ...sql import sqltypes
 from ...types import NVARCHAR
 from ...types import VARCHAR
@@ -216,6 +217,33 @@ class INTERVAL(sqltypes.NativeForEmulated, sqltypes._AbstractInterval):
         )
 
 
+class TIMESTAMP(sqltypes.TIMESTAMP):
+    """Oracle implementation of ``TIMESTAMP``, which supports additional
+    Oracle-specific modes
+
+    .. versionadded:: 2.0
+
+    """
+
+    def __init__(self, timezone: bool = False, local_timezone: bool = False):
+        """Construct a new :class:`_oracle.TIMESTAMP`.
+
+        :param timezone: boolean.  Indicates that the TIMESTAMP type should
+         use Oracle's ``TIMESTAMP WITH TIME ZONE`` datatype.
+
+        :param local_timezone: boolean.  Indicates that the TIMESTAMP type
+         should use Oracle's ``TIMESTAMP WITH LOCAL TIME ZONE`` datatype.
+
+
+        """
+        if timezone and local_timezone:
+            raise exc.ArgumentError(
+                "timezone and local_timezone are mutually exclusive"
+            )
+        super().__init__(timezone=timezone)
+        self.local_timezone = local_timezone
+
+
 class ROWID(sqltypes.TypeEngine):
     """Oracle ROWID type.