From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Wed, 7 Sep 2022 23:00:31 +0000 (-0400)
Subject: add docs for session.get()
X-Git-Tag: rel_2_0_0b1~71
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=cc72081b0c32dbd089fb9601747f448b65414640;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

add docs for session.get()

also use the term "primary key" a bit more

Change-Id: Ib654b30a9d06a2aeed019b4754db920afe05d774
References: https://twitter.com/encthenet/status/1567644850471989248
---

diff --git a/doc/build/orm/session_basics.rst b/doc/build/orm/session_basics.rst
index bad011d8e3..96b9d8b5ca 100644
--- a/doc/build/orm/session_basics.rst
+++ b/doc/build/orm/session_basics.rst
@@ -503,6 +503,29 @@ behavior.
     :ref:`faq_session_rollback` - further background on why
     :meth:`_orm.Session.rollback` must be called when a flush fails.
 
+.. _session_get:
+
+Get by Primary Key
+------------------
+
+As the :class:`_orm.Session` makes use of an :term:`identity map` which refers
+to current in-memory objects by primary key, the :meth:`_orm.Session.get`
+method is provided as a means of locating objects by primary key, first
+looking within the current identity map and then querying the database
+for non present values.  Such as, to locate a ``User`` entity with primary key
+identity ``(5, )``::
+
+    my_user = session.get(User, 5)
+
+The :meth:`_orm.Session.get` also includes calling forms for composite primary
+key values, which may be passed as tuples or dictionaries, as well as
+additional parameters which allow for specific loader and execution options.
+See :meth:`_orm.Session.get` for the complete parameter list.
+
+.. seealso::
+
+    :meth:`_orm.Session.get`
+
 .. _session_expiring:
 
 Expiring / Refreshing
@@ -555,9 +578,11 @@ ways to refresh its contents with new data from the current transaction:
 
   ..
 
-* **the populate_existing() method** - this method is actually on the
-  :class:`_orm.Query` object as :meth:`_orm.Query.populate_existing`
-  and indicates that it should return objects that are unconditionally
+* **the populate_existing() method or execution option** - This is now
+  an execution option documented at :ref:`orm_queryguide_populate_existing`; in
+  legacy form it's found on the :class:`_orm.Query` object as the
+  :meth:`_orm.Query.populate_existing` method. This operation in either form
+  indicates that objects being returned from a query should be unconditionally
   re-populated from their contents in the database::
 
     u2 = session.scalars(
diff --git a/doc/build/tutorial/orm_data_manipulation.rst b/doc/build/tutorial/orm_data_manipulation.rst
index ca955d0237..b0b67f53c4 100644
--- a/doc/build/tutorial/orm_data_manipulation.rst
+++ b/doc/build/tutorial/orm_data_manipulation.rst
@@ -173,8 +173,8 @@ the ``id`` attribute::
    INSERT many rows at once while still being able to retrieve the primary key
    values.
 
-Identity Map
-^^^^^^^^^^^^
+Getting Objects by Primary Key from the Identity Map
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 The primary key identity of the objects are significant to the :class:`_orm.Session`,
 as the objects are now linked to this identity in memory using a feature