class BaseModel(object):
""" Base class for OpenERP models.
OpenERP models are created by inheriting from this class' subclasses:
* :class:`Model` for regular database-persisted models 常用数据库模型
* :class:`TransientModel` for temporary data, stored in the database but
automatically vacuumed every so often 临时模型
* :class:`AbstractModel` for abstract super classes meant to be shared by
multiple inheriting model 抽象模型 不保存
The system automatically instantiates every model once per database. Those
instances represent the available models on each database, and depend on
which modules are installed on that database. The actual class of each
instance is built from the Python classes that create and inherit from the
corresponding model.
Every model instance is a "recordset", i.e., an ordered collection of
records of the model. Recordsets are returned by methods like
:meth:`~.browse`, :meth:`~.search`, or field accesses. Records have no
explicit representation: a record is represented as a recordset of one
record.
To create a class that should not be instantiated, the _register class
attribute may be set to False.
"""
__metaclass__ = MetaModel
_auto = True # create database backend
_register = False # Set to false if the model shouldn't be automatically discovered.
_name = None
_columns = {}
_constraints = []
_custom = False
_defaults = {}
_rec_name = None
_parent_name = 'parent_id'
_parent_store = False
_parent_order = False
_date_name = 'date'
_order = 'id'
_sequence = None
_description = None
_needaction = False
_translate = True # set to False to disable translations export for this model
# dict of {field:method}, with method returning the (name_get of records, {id: fold})
# to include in the _read_group, if grouped on this field
_group_by_full = {}
# Transience
_transient = False # True in a TransientModel
# structure:
# { 'parent_model': 'm2o_field', ... }
_inherits = {}
# Mapping from inherits'd field name to triple (m, r, f, n) where m is the
# model from which it is inherits'd, r is the (local) field towards m, f
# is the _column object itself, and n is the original (i.e. top-most)
# parent model.
# Example:
# { 'field_name': ('parent_model', 'm2o_field_to_reach_parent',
# field_column_obj, origina_parent_model), ... }
_inherit_fields = {}
_table = None
_log_create = False
_sql_constraints = []
# model dependencies, for models backed up by sql views:
# {model_name: field_names, ...}
_depends = {}
CONCURRENCY_CHECK_FIELD = '__last_update'
