mirror of
https://github.com/janeczku/calibre-web
synced 2024-11-28 20:39:59 +00:00
74 lines
2.5 KiB
Python
74 lines
2.5 KiB
Python
# Copyright (C) 2013 the SQLAlchemy authors and contributors <see AUTHORS file>
|
|
#
|
|
# This module is part of SQLAlchemy and is released under
|
|
# the MIT License: http://www.opensource.org/licenses/mit-license.php
|
|
from sqlalchemy.schema import ColumnCollectionConstraint
|
|
from sqlalchemy.sql import expression
|
|
|
|
class ExcludeConstraint(ColumnCollectionConstraint):
|
|
"""A table-level EXCLUDE constraint.
|
|
|
|
Defines an EXCLUDE constraint as described in the `postgres
|
|
documentation`__.
|
|
|
|
__ http://www.postgresql.org/docs/9.0/static/sql-createtable.html#SQL-CREATETABLE-EXCLUDE
|
|
"""
|
|
|
|
__visit_name__ = 'exclude_constraint'
|
|
|
|
where = None
|
|
|
|
def __init__(self, *elements, **kw):
|
|
"""
|
|
:param \*elements:
|
|
A sequence of two tuples of the form ``(column, operator)`` where
|
|
column must be a column name or Column object and operator must
|
|
be a string containing the operator to use.
|
|
|
|
:param name:
|
|
Optional, the in-database name of this constraint.
|
|
|
|
:param deferrable:
|
|
Optional bool. If set, emit DEFERRABLE or NOT DEFERRABLE when
|
|
issuing DDL for this constraint.
|
|
|
|
:param initially:
|
|
Optional string. If set, emit INITIALLY <value> when issuing DDL
|
|
for this constraint.
|
|
|
|
:param using:
|
|
Optional string. If set, emit USING <index_method> when issuing DDL
|
|
for this constraint. Defaults to 'gist'.
|
|
|
|
:param where:
|
|
Optional string. If set, emit WHERE <predicate> when issuing DDL
|
|
for this constraint.
|
|
|
|
"""
|
|
ColumnCollectionConstraint.__init__(
|
|
self,
|
|
name=kw.get('name'),
|
|
deferrable=kw.get('deferrable'),
|
|
initially=kw.get('initially'),
|
|
*[col for col, op in elements]
|
|
)
|
|
self.operators = {}
|
|
for col_or_string, op in elements:
|
|
name = getattr(col_or_string, 'name', col_or_string)
|
|
self.operators[name] = op
|
|
self.using = kw.get('using', 'gist')
|
|
where = kw.get('where')
|
|
if where:
|
|
self.where = expression._literal_as_text(where)
|
|
|
|
def copy(self, **kw):
|
|
elements = [(col, self.operators[col])
|
|
for col in self.columns.keys()]
|
|
c = self.__class__(name=self.name,
|
|
deferrable=self.deferrable,
|
|
initially=self.initially,
|
|
*elements)
|
|
c.dispatch._update(self.dispatch)
|
|
return c
|
|
|