diff options
Diffstat (limited to 'lib/sqlalchemy/orm/mapper.py')
| -rw-r--r-- | lib/sqlalchemy/orm/mapper.py | 36 |
1 files changed, 32 insertions, 4 deletions
diff --git a/lib/sqlalchemy/orm/mapper.py b/lib/sqlalchemy/orm/mapper.py index 2a227f9da..0241a3123 100644 --- a/lib/sqlalchemy/orm/mapper.py +++ b/lib/sqlalchemy/orm/mapper.py @@ -289,10 +289,29 @@ class Mapper( :param column_prefix: A string which will be prepended to the mapped attribute name when :class:`_schema.Column` objects are automatically assigned as attributes to the - mapped class. Does not affect explicitly specified - column-based properties. - - See the section :ref:`column_prefix` for an example. + mapped class. Does not affect :class:`.Column` objects that + are mapped explicitly in the :paramref:`.Mapper.properties` + dictionary. + + This parameter is typically useful with imperative mappings + that keep the :class:`.Table` object separate. Below, assuming + the ``user_table`` :class:`.Table` object has columns named + ``user_id``, ``user_name``, and ``password``:: + + class User(Base): + __table__ = user_table + __mapper_args__ = {'column_prefix':'_'} + + The above mapping will assign the ``user_id``, ``user_name``, and + ``password`` columns to attributes named ``_user_id``, + ``_user_name``, and ``_password`` on the mapped ``User`` class. + + The :paramref:`.Mapper.column_prefix` parameter is uncommon in + modern use. For dealing with reflected tables, a more flexible + approach to automating a naming scheme is to intercept the + :class:`.Column` objects as they are reflected; see the section + :ref:`mapper_automated_reflection_schemes` for notes on this usage + pattern. :param concrete: If True, indicates this mapper should use concrete table inheritance with its parent mapper. @@ -580,12 +599,21 @@ class Mapper( based on all those :class:`.MapperProperty` instances declared in the declared class body. + .. seealso:: + + :ref:`orm_mapping_properties` - in the + :ref:`orm_mapping_classes_toplevel` + :param primary_key: A list of :class:`_schema.Column` objects which define the primary key to be used against this mapper's selectable unit. This is normally simply the primary key of the ``local_table``, but can be overridden here. + .. seealso:: + + :ref:`mapper_primary_key` - background and example use + :param version_id_col: A :class:`_schema.Column` that will be used to keep a running version id of rows in the table. This is used to detect concurrent updates or |