class DialectKWArgs: (source)
Known subclasses: sqlalchemy.sql.dml.UpdateBase, sqlalchemy.sql.schema.Column, sqlalchemy.sql.schema.Constraint, sqlalchemy.sql.schema.ForeignKey, sqlalchemy.sql.schema.Index, sqlalchemy.sql.schema.Table
Establish the ability for a class to have dialect-specific arguments with defaults and constructor validation. The :class:`.DialectKWArgs` interacts with the :attr:`.DefaultDialect.construct_arguments` present on a dialect. .. seealso:: :attr:`.DefaultDialect.construct_arguments`
| Class Method | argument |
Add a new kind of dialect-specific keyword argument for this class. |
| Class Variable | __slots__ |
Undocumented |
| Property | dialect |
A collection of keyword arguments specified as dialect-specific options to this construct. |
| Property | dialect |
A collection of keyword arguments specified as dialect-specific options to this construct. |
| Property | kwargs |
A synonym for :attr:`.DialectKWArgs.dialect_kwargs`. |
| Method | _kw |
Undocumented |
| Method | _validate |
Undocumented |
| Class Variable | _dialect |
Undocumented |
| Class Variable | _kw |
Undocumented |
Add a new kind of dialect-specific keyword argument for this class. E.g.:: Index.argument_for("mydialect", "length", None) some_index = Index('a', 'b', mydialect_length=5) The :meth:`.DialectKWArgs.argument_for` method is a per-argument way adding extra arguments to the :attr:`.DefaultDialect.construct_arguments` dictionary. This dictionary provides a list of argument names accepted by various schema-level constructs on behalf of a dialect. New dialects should typically specify this dictionary all at once as a data member of the dialect class. The use case for ad-hoc addition of argument names is typically for end-user code that is also using a custom compilation scheme which consumes the additional arguments. :param dialect_name: name of a dialect. The dialect must be locatable, else a :class:`.NoSuchModuleError` is raised. The dialect must also include an existing :attr:`.DefaultDialect.construct_arguments` collection, indicating that it participates in the keyword-argument validation and default system, else :class:`.ArgumentError` is raised. If the dialect does not include this collection, then any keyword argument can be specified on behalf of this dialect already. All dialects packaged within SQLAlchemy include this collection, however for third party dialects, support may vary. :param argument_name: name of the parameter. :param default: default value of the parameter. .. versionadded:: 0.9.4
A collection of keyword arguments specified as dialect-specific options to this construct. The arguments are present here in their original ``<dialect>_<kwarg>`` format. Only arguments that were actually passed are included; unlike the :attr:`.DialectKWArgs.dialect_options` collection, which contains all options known by this dialect including defaults. The collection is also writable; keys are accepted of the form ``<dialect>_<kwarg>`` where the value will be assembled into the list of options. .. versionadded:: 0.9.2 .. versionchanged:: 0.9.4 The :attr:`.DialectKWArgs.dialect_kwargs` collection is now writable. .. seealso:: :attr:`.DialectKWArgs.dialect_options` - nested dictionary form
A collection of keyword arguments specified as dialect-specific options to this construct. This is a two-level nested registry, keyed to ``<dialect_name>`` and ``<argument_name>``. For example, the ``postgresql_where`` argument would be locatable as:: arg = my_object.dialect_options['postgresql']['where'] .. versionadded:: 0.9.2 .. seealso:: :attr:`.DialectKWArgs.dialect_kwargs` - flat dictionary form