Surface driver connection object when using a proxied dialect

Improve the interface used by adapted drivers, like the asyncio ones,
to access the actual connection object returned by the driver.

The :class:`_engine._ConnectionRecord` and
:class:`_engine._ConnectionFairy` now have two new attributes:

* ``dbapi_connection`` always represents a DBAPI compatible
object.  For pep-249 drivers, this is the DBAPI connection as it always
has been, previously accessed under the ``.connection`` attribute.
For asyncio drivers that SQLAlchemy adapts into a pep-249 interface,
the returned object will normally be a SQLAlchemy adaption object
called :class:`_engine.AdaptedConnection`.
* ``driver_connection`` always represents the actual connection object
maintained by the third party pep-249 DBAPI or async driver in use.
For standard pep-249 DBAPIs, this will always be the same object
as that of the ``dbapi_connection``.  For an asyncio driver, it will be
the underlying asyncio-only connection object.

The ``.connection`` attribute remains available and is now a legacy alias
of ``.dbapi_connection``.

Fixes: #6832
Change-Id: Ib72f97deefca96dce4e61e7c38ba430068d6a82e

1 files changed, 4 insertions, 4 deletions

diff --git a/lib/sqlalchemy/dialects/sqlite/pysqlite.py b/lib/sqlalchemy/dialects/sqlite/pysqlite.py
index 0f96e8830..e9d5d9682 100644
--- a/lib/sqlalchemy/dialects/sqlite/pysqlite.py
+++ b/lib/sqlalchemy/dialects/sqlite/pysqlite.py
@@ -499,8 +499,8 @@ class SQLiteDialect_pysqlite(SQLiteDialect):
     )
 
     def set_isolation_level(self, connection, level):
-        if hasattr(connection, "connection"):
-            dbapi_connection = connection.connection
+        if hasattr(connection, "dbapi_connection"):
+            dbapi_connection = connection.dbapi_connection
         else:
             dbapi_connection = connection
 
@@ -521,8 +521,8 @@ class SQLiteDialect_pysqlite(SQLiteDialect):
             return re.search(a, b) is not None
 
         def set_regexp(connection):
-            if hasattr(connection, "connection"):
-                dbapi_connection = connection.connection
+            if hasattr(connection, "dbapi_connection"):
+                dbapi_connection = connection.dbapi_connection
             else:
                 dbapi_connection = connection
             dbapi_connection.create_function(