UniqueConstraint with func

[lestat]

Can I add UniqueConstraint like this?


from sqlalchemy import func
from sqlalchemy.schema import UniqueConstraint
from sqlalchemy.dialects import postgres

class UserIp(db.Model):
__tablename__ = 'user_ip'

__table_args__ = (
UniqueConstraint('user_id', func.md5('ip')),
)

user_id = db.Column(db.Integer, db.ForeignKey('user.id'),
primary_key=True, default=None)
ip = db.Column(postgres.CIDR, nullable=False,
default='127.0.0.1/32')



It raise exception:

/usr/lib/python2.7/site-packages/flaskext/sqlalchemy.pyc in
__init__(self, name, bases, d)
465 def __init__(self, name, bases, d):
466 bind_key = d.pop('__bind_key__', None)
--> 467 DeclarativeMeta.__init__(self, name, bases, d)
468 if bind_key is not None:
469 self.__table__.info['bind_key'] = bind_key

/usr/lib/python2.7/site-packages/sqlalchemy/ext/declarative.pyc in
__init__(cls, classname, bases, dict_)
1257 return type.__init__(cls, classname, bases, dict_)
1258 else:
-> 1259 _as_declarative(cls, classname, cls.__dict__)
1260 return type.__init__(cls, classname, bases, dict_)
1261

/usr/lib/python2.7/site-packages/sqlalchemy/ext/declarative.pyc in
_as_declarative(cls, classname, dict_)
1156 cls.__table__ = table = Table(tablename,
cls.metadata,
1157 *(tuple(cols) +
tuple(args)),
-> 1158 **table_kw)
1159 else:
1160 table = cls.__table__

/usr/lib/python2.7/site-packages/sqlalchemy/schema.pyc in __new__(cls,
*args, **kw)
267 metadata._add_table(name, schema, table)
268 try:
--> 269 table._init(name, metadata, *args, **kw)
270 table.dispatch.after_parent_attach(table,
metadata)
271 return table

/usr/lib/python2.7/site-packages/sqlalchemy/schema.pyc in _init(self,
name, metadata, *args, **kwargs)
342 # initialize all the column, etc. objects. done after
reflection to
343 # allow user-overrides
--> 344 self._init_items(*args)
345
346 @property

/usr/lib/python2.7/site-packages/sqlalchemy/schema.pyc in
_init_items(self, *args)
62 for item in args:
63 if item is not None:
---> 64 item._set_parent_with_dispatch(self)
65
66 def get_children(self, **kwargs):

/usr/lib/python2.7/site-packages/sqlalchemy/events.pyc in
_set_parent_with_dispatch(self, parent)
228 def _set_parent_with_dispatch(self, parent):
229 self.dispatch.before_parent_attach(self, parent)
--> 230 self._set_parent(parent)
231 self.dispatch.after_parent_attach(self, parent)
232

/usr/lib/python2.7/site-packages/sqlalchemy/schema.pyc in
_set_parent(self, table)
1827
1828 def _set_parent(self, table):
-> 1829 ColumnCollectionMixin._set_parent(self, table)
1830 Constraint._set_parent(self, table)
1831

/usr/lib/python2.7/site-packages/sqlalchemy/schema.pyc in
_set_parent(self, table)
1801 if isinstance(col, basestring):
1802 col = table.c[col]
-> 1803 self.columns.add(col)
1804
1805 class ColumnCollectionConstraint(ColumnCollectionMixin,
Constraint):

/usr/lib/python2.7/site-packages/sqlalchemy/sql/expression.pyc in
add(self, column)
2135
2136 """
-> 2137 self[column.key] = column
2138
2139 def __delitem__(self, key):

AttributeError: 'Function' object has no attribute 'key'




Thanks!

[Michael Bayer]

id never heard of a functional unique constraint but there you go, here's a stack overflow answer for this one:

http://stackoverflow.com/questions/1510018/compound-uniqueconstraint-with-a-function

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