docs: explain missing preference header

docs/references/api/preferences.rst

@@ -12,7 +12,7 @@ The following preferences are supported.
 - ``Prefer: return``. See :ref:`prefer_return`.
 - ``Prefer: count``. See :ref:`prefer_count`.
 - ``Prefer: resolution``. See :ref:`prefer_resolution`.
-- ``Prefer: missing``. See :ref:`bulk_insert_default`.
+- ``Prefer: missing``. See :ref:`prefer_missing`.
 - ``Prefer: max-affected``, See :ref:`prefer_max_affected`.
 - ``Prefer: tx``. See :ref:`prefer_tx`.
 
@@ -196,6 +196,47 @@ The ``tx`` preference can be set to specify if the :ref:`transaction <transactio
   {"id": 35, "name": "Project X"}
 
 
+.. _prefer_missing:
+
+Missing
+=======
+
+When doing ``POST`` and ``PATCH`` requests, any missing columns in the payload will be inserted as ``null`` value by default. To use the ``DEFAULT`` column value instead, use the ``Prefer: missing=default`` header.
+
+Having:
+
+.. code-block:: postgres
+
+  create table foo (
+    id bigint generated by default as identity primary key
+  , bar text
+  , baz int default 100
+  );
+
+A request:
+
+.. code-block:: bash
+
+  curl "http://localhost:3000/foo?columns=id,bar,baz" \
+    -H "Content-Type: application/json" \
+    -H "Prefer: missing=default, return=representation" \
+    -d @- << EOF
+      [
+        { "bar": "val1" },
+        { "bar": "val2", "baz": 15 }
+      ]
+  EOF
+
+Will result in:
+
+.. code-block:: json
+
+  [
+    { "id":  1, "bar": "val1", "baz": 100 },
+    { "id":  2, "bar": "val2", "baz": 15 }
+  ]
+
+
 .. _prefer_max_affected:
 
 Max Affected

docs/references/api/tables_views.rst

@@ -539,45 +539,6 @@ To bulk insert JSON post an array of objects having all-matching keys
     ]
   EOF
 
-.. _bulk_insert_default:
-
-Bulk Insert with Default Values
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-Any missing columns in the payload will be inserted as ``null`` values. To use the ``DEFAULT`` column value instead, use the ``Prefer: missing=default`` header.
-
-Having:
-
-.. code-block:: postgres
-
-  create table foo (
-    id bigint generated by default as identity primary key
-  , bar text
-  , baz int default 100
-  );
-
-A request:
-
-.. code-block:: bash
-
-  curl "http://localhost:3000/foo?columns=id,bar,baz" \
-    -H "Content-Type: application/json" \
-    -H "Prefer: missing=default, return=representation" \
-    -d @- << EOF
-      [
-        { "bar": "val1" },
-        { "bar": "val2", "baz": 15 }
-      ]
-  EOF
-
-Will result in:
-
-.. code-block:: json
-
-  [
-    { "id":  1, "bar": "val1", "baz": 100 },
-    { "id":  2, "bar": "val2", "baz": 15 }
-  ]
 
 .. _specify_columns:
 
@@ -651,7 +612,7 @@ You can make an upsert with :code:`POST` and the :code:`Prefer: resolution=merge
 By default, upsert operates based on the primary key columns, so you must specify all of them.
 You can also choose to ignore the duplicates with :code:`Prefer: resolution=ignore-duplicates`.
 Upsert works best when the primary key is natural (e.g. ``sku``).
-However, it can work with surrogate primary keys (e.g. ``id serial primary key``), if you also do a :ref:`bulk_insert_default`:
+However, it can work with surrogate primary keys (e.g. ``id serial primary key``), if you also do a :ref:`bulk_insert` with :ref:`prefer_missing`:
 
 .. code-block:: bash