DOCS-14158 Adding blurb to cover expression operator and upsert flag.

Author: ianf-mongodb

source/reference/method/db.collection.update.txt

@@ -252,6 +252,12 @@ privileges.
 Behavior
 --------
 
+Using ``$expr`` in an Update with ``Upsert``
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Attempting to use the :manual:`$expr </reference/operator/query/expr/>` 
+operator with the upsert flag set to ``true`` will generate an error.
+
 .. _update-sharded-collection:
 
 Sharded Collections
@@ -412,6 +418,10 @@ Examples
 The following tabs showcase a variety of common
 :method:`~db.collection.update()` operations.
 
+.. include:: /includes/fact-update-example-docs-intro.rst
+
+.. include:: /includes/fact-update-example-docs.rst
+
 .. tabs::
 
    .. tab:: Set
@@ -420,10 +430,6 @@ The following tabs showcase a variety of common
       Use Update Operator Expressions (``$inc`` and ``$set``)
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      .. include:: /includes/fact-update-example-docs-intro.rst
-
-      .. include:: /includes/fact-update-example-docs.rst
-
       If the ``<update>`` document contains :ref:`update operator
       <update-operators>` modifiers, such as those using the
       :update:`$set` modifier, then:
@@ -524,10 +530,6 @@ The following tabs showcase a variety of common
       Push Elements to Existing Array (``$push``)
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      .. include:: /includes/fact-update-example-docs-intro.rst
-
-      .. include:: /includes/fact-update-example-docs.rst
-
       The following operation uses the :update:`$push` update
       operator to append a new object to the ``ratings`` array.
 
@@ -576,10 +578,6 @@ The following tabs showcase a variety of common
       Remove Fields (``$unset``)
       ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      .. include:: /includes/fact-update-example-docs-intro.rst
-
-      .. include:: /includes/fact-update-example-docs.rst
-
       The following operation uses the :update:`$unset` operator to remove
       the ``tags`` field from the document with ``{ _id: 1 }``.
 
@@ -622,93 +620,12 @@ The following tabs showcase a variety of common
 
          :update:`$unset`, :update:`$rename`, :doc:`/reference/operator/update`
 
-   .. tab:: Replace
-      :tabid: replace-doc
-
-      Replace Entire Document (``$update``)
-      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-      .. include:: /includes/fact-update-example-docs-intro.rst
-
-      .. include:: /includes/fact-update-example-docs.rst
-
-      If the ``<update>`` document contains *only* ``field:value``
-      expressions, then:
-
-      - The :method:`db.collection.update()` method *replaces* the matching
-        document with the ``<update>`` document. The
-        :method:`db.collection.update()` method *does not* replace the
-        ``_id`` value.
-
-      - :method:`db.collection.update()` *cannot* update multiple
-        documents.
-
-      The following operation passes an ``<update>`` document that contains
-      only field and value pairs. The ``<update>`` document completely
-      replaces the original document except for the ``_id`` field.
-
-      You can use the web shell below to insert the sample
-      documents and execute the example update operation:
-
-      .. include:: /includes/fact-mws.rst
-
-      .. code-block:: javascript
-
-         db.books.update(
-            { _id: 2 },
-            {
-              item: "XYZ123",
-              stock: 10,
-              info: { publisher: "2255", pages: 150 },
-              tags: [ "baking", "cooking" ]
-            }
-         )
-
-      The updated document contains *only* the fields from the
-      replacement document and the ``_id`` field. As such, the fields
-      ``ratings`` and ``reorder`` no longer exist in the updated
-      document since the fields were not in the replacement document.
-
-      .. code-block:: javascript
-
-         {
-            "_id" : 2,
-            "item" : "XYZ123",
-            "stock" : 10,
-            "info" : { "publisher" : "2255", "pages" : 150 },
-            "tags" : [ "baking", "cooking" ]
-         }
-
-      This operation corresponds to the following SQL statements:
-
-      .. code-block:: sql
-
-         DELETE from books WHERE _id = 2
-
-         INSERT INTO books
-                     (_id,
-                      item,
-                      stock,
-                      publisher,
-                      pages,
-                      tags)
-         VALUES     (2,
-                     "xyz123",
-                     10,
-                     "2255",
-                     150,
-                     "baking,cooking")
-
    .. tab:: Multiple
       :tabid: update-multiple
 
       Update Multiple Documents (``$update`` With ``multi``)
       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-      .. include:: /includes/fact-update-example-docs-intro.rst
-
-      .. include:: /includes/fact-update-example-docs.rst
-
       If ``multi`` is set to ``true``, the
       :method:`db.collection.update()` method updates *all* documents
       that meet the ``<query>`` criteria. The ``multi`` update