147 lines
4.6 KiB
Python
147 lines
4.6 KiB
Python
# sqlalchemy/naming.py
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# Copyright (C) 2005-2017 the SQLAlchemy authors and contributors
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# <see AUTHORS file>
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#
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# This module is part of SQLAlchemy and is released under
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# the MIT License: http://www.opensource.org/licenses/mit-license.php
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"""Establish constraint and index naming conventions.
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"""
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from .schema import Constraint, ForeignKeyConstraint, PrimaryKeyConstraint, \
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UniqueConstraint, CheckConstraint, Index, Table, Column
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from .. import event, events
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from .. import exc
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from .elements import _truncated_label, _defer_name, _defer_none_name, conv
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import re
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class ConventionDict(object):
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def __init__(self, const, table, convention):
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self.const = const
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self._is_fk = isinstance(const, ForeignKeyConstraint)
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self.table = table
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self.convention = convention
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self._const_name = const.name
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def _key_table_name(self):
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return self.table.name
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def _column_X(self, idx):
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if self._is_fk:
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fk = self.const.elements[idx]
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return fk.parent
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else:
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return list(self.const.columns)[idx]
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def _key_constraint_name(self):
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if isinstance(self._const_name, (type(None), _defer_none_name)):
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raise exc.InvalidRequestError(
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"Naming convention including "
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"%(constraint_name)s token requires that "
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"constraint is explicitly named."
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)
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if not isinstance(self._const_name, conv):
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self.const.name = None
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return self._const_name
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def _key_column_X_name(self, idx):
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return self._column_X(idx).name
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def _key_column_X_label(self, idx):
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return self._column_X(idx)._label
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def _key_referred_table_name(self):
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fk = self.const.elements[0]
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refs = fk.target_fullname.split(".")
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if len(refs) == 3:
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refschema, reftable, refcol = refs
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else:
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reftable, refcol = refs
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return reftable
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def _key_referred_column_X_name(self, idx):
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fk = self.const.elements[idx]
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refs = fk.target_fullname.split(".")
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if len(refs) == 3:
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refschema, reftable, refcol = refs
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else:
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reftable, refcol = refs
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return refcol
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def __getitem__(self, key):
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if key in self.convention:
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return self.convention[key](self.const, self.table)
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elif hasattr(self, '_key_%s' % key):
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return getattr(self, '_key_%s' % key)()
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else:
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col_template = re.match(r".*_?column_(\d+)_.+", key)
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if col_template:
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idx = col_template.group(1)
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attr = "_key_" + key.replace(idx, "X")
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idx = int(idx)
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if hasattr(self, attr):
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return getattr(self, attr)(idx)
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raise KeyError(key)
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_prefix_dict = {
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Index: "ix",
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PrimaryKeyConstraint: "pk",
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CheckConstraint: "ck",
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UniqueConstraint: "uq",
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ForeignKeyConstraint: "fk"
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}
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def _get_convention(dict_, key):
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for super_ in key.__mro__:
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if super_ in _prefix_dict and _prefix_dict[super_] in dict_:
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return dict_[_prefix_dict[super_]]
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elif super_ in dict_:
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return dict_[super_]
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else:
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return None
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def _constraint_name_for_table(const, table):
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metadata = table.metadata
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convention = _get_convention(metadata.naming_convention, type(const))
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if isinstance(const.name, conv):
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return const.name
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elif convention is not None and \
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not isinstance(const.name, conv) and \
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(
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const.name is None or
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"constraint_name" in convention or
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isinstance(const.name, _defer_name)):
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return conv(
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convention % ConventionDict(const, table,
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metadata.naming_convention)
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)
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elif isinstance(convention, _defer_none_name):
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return None
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@event.listens_for(Constraint, "after_parent_attach")
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@event.listens_for(Index, "after_parent_attach")
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def _constraint_name(const, table):
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if isinstance(table, Column):
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# for column-attached constraint, set another event
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# to link the column attached to the table as this constraint
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# associated with the table.
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event.listen(table, "after_parent_attach",
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lambda col, table: _constraint_name(const, table)
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)
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elif isinstance(table, Table):
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if isinstance(const.name, (conv, _defer_name)):
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return
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newname = _constraint_name_for_table(const, table)
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if newname is not None:
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const.name = newname
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