Update docs

Author: David Andersson

docs/source/examples/index.rst

@@ -9,6 +9,7 @@ Examples
    alembic
    simple
    default
+   server_default
    read_only
    write_only
    relationship/index

docs/source/examples/server_default.rst

@@ -0,0 +1,44 @@
+Server Default
+==============
+
+OpenAlchemy supports defining a default value generated by the database
+through the :samp:`x-server-default` extension property. It is similar to the
+OpenAPI :samp:`default` property except that the default value is calculated
+by the database rather than the application.
+
+.. seealso::
+
+    :ref:`server-default`
+      OpenAlchemy documentation for the server default value.
+
+    :ref:`default`
+      OpenAlchemy documentation for the default value.
+
+    `SQLAlchemy Server Default <https://docs.sqlalchemy.org/en/13/core/metadata.html#sqlalchemy.schema.Column.params.server_default>`_
+      Documentation for the SQLAlchemy server default.
+
+The following example defines a default value for the :samp:`name` property of
+:samp:`Employee`:
+
+.. literalinclude:: ../../../examples/server_default/example-spec.yml
+    :language: yaml
+    :linenos:
+
+The following file uses OpenAlchemy to generate the SQLAlchemy models:
+
+.. literalinclude:: ../../../examples/server_default/models.py
+    :language: python
+    :linenos:
+
+The SQLAlchemy models generated by OpenAlchemy are equivalent to the following
+traditional models file:
+
+.. literalinclude:: ../../../examples/server_default/models_traditional.py
+    :language: python
+    :linenos:
+
+OpenAlchemy will generate the following typed models:
+
+.. literalinclude:: ../../../examples/server_default/models_auto.py
+    :language: python
+    :linenos:

docs/source/technical_details/column_modifiers.rst

@@ -457,6 +457,45 @@ OpenAlchemy.
     `SQLAlchemy "Scalar Default" <https://docs.sqlalchemy.org/en/13/core/defaults.html#scalar-defaults>`_
       Documentation for the scalar default value in SQLAlchemy.
 
+.. _server-default:
+
+Server Default
+--------------
+
+To add a default value for a column to be generated by the database, use the
+:samp:`x-server-default` extension property:
+
+.. code-block:: yaml
+    :linenos:
+
+    Employee:
+      type: object
+      x-tablename: employee
+      properties:
+        id:
+          type: integer
+        name:
+          type: string
+          x-server-default: Unknown
+
+The default value is added to the column constructor using the "Server
+Default" in SQLAlchemy. The following property types support a server default
+value (including all their formats supported by OpenAlchemy):
+
+* :samp:`integer`,
+* :samp:`number`,
+* :samp:`string` and
+* :samp:`boolean`.
+
+Adding a server default to a :samp:`object` or :samp:`array` type is not valid
+in OpenAlchemy. Server default is also not supported by any property that sets
+:samp:`x-json` to :samp:`true`.
+
+.. seealso::
+
+    `SQLAlchemy Server Default <https://docs.sqlalchemy.org/en/13/core/metadata.html#sqlalchemy.schema.Column.params.server_default>`_
+      Documentation for the SQLAlchemy server default.
+
 .. _read-only:
 
 readOnly

examples/server_default/example-spec.yml

@@ -35,4 +35,4 @@ components:
           type: string
           description: The name of the employee.
           example: David Andersson
-          x-server-default: "Unknown"
+          x-server-default: Unknown

open_alchemy/schemas/validation/property_/json.py

@@ -46,6 +46,13 @@ def check(schemas: oa_types.Schemas, schema: oa_types.Schema) -> types.Result:
         )
         if autoincrement is not None:
             return types.Result(False, "json properties do not support x-autoincrement")
+        server_default = helpers.peek.peek_key(
+            schema=schema, schemas=schemas, key="x-server-default"
+        )
+        if server_default is not None:
+            return types.Result(
+                False, "json properties do not support x-server-default"
+            )
         # Checks kwargs, foreign key and foreign key kwargs
         kwargs_result = simple.check_kwargs(schema=schema, schemas=schemas)
         if kwargs_result is not None:

tests/open_alchemy/schemas/validation/property_/test_json.py

@@ -158,6 +158,12 @@
         (False, "json properties do not support x-autoincrement"),
         id="x-autoincrement defined",
     ),
+    pytest.param(
+        {"x-server-default": "False"},
+        {},
+        (False, "json properties do not support x-server-default"),
+        id="x-server-default defined",
+    ),
     pytest.param(
         {"x-foreign-key": True},
         {},