Here's my reworking of the example for time types:
"""
from datetime import datetime, timedelta, date
from sqlalchemy import MetaData, Table, Column, DateTime, Date,
Interval
from sqlalchemy.orm import mapper, create_session
metadata = MetaData('postgresql:///avdd')
interval_table1 = Table('period1', metadata,
Column('start', DateTime, primary_key=True),
Column('end', DateTime, primary_key=True))
interval_table2 = Table('period2', metadata,
Column('start', DateTime, primary_key=True),
Column('length', Interval, primary_key=True))
metadata.create_all()
class BasePeriod(object):
@hybrid
def contains(self, instant):
return (self.start <= instant) & (instant < self.end)
@hybrid
def intersects(self, other):
return (self.start < other.end) & (self.end > other.start)
def __repr__(self):
return "%s(%s..%s)" % (self.__class__.__name__, self.start,
self.end)
class Period1(BasePeriod):
length = hybrid_property(lambda s: s.end - s.start)
def __init__(self, start, end):
self.start = start
self.end = end
mapper(Period1, interval_table1)
class Period2(BasePeriod):
end = hybrid_property(lambda s: s.start + s.length)
def __init__(self, start, length):
self.start = start
self.length = length
mapper(Period2, interval_table2)
session = create_session()
intervals = [timedelta(seconds=1),
timedelta(1),
timedelta(366)]
instants = [datetime.now(),
datetime(2000, 1, 2, 3, 4, 5),
datetime(1987, 6, 5, 4, 3, 2, 1)]
session.begin()
for i in instants:
for j in intervals:
session.add(Period1(i, i + j))
session.add(Period2(i, j))
session.commit()
session.expunge_all()
for ptype in (Period1, Period2):
q = session.query(ptype)
for p in q.filter(ptype.length < timedelta(10)):
print p, p.length
for p in q.filter(ptype.end < date.today()):
print p, p.length
now = datetime.now()
for p in q.filter(ptype.contains(now)):
print p, p.contains(now)
other = Period2(datetime.now(), timedelta(7))
for p in q.filter(ptype.intersects(other)).order_by(ptype.length):
print p, p.intersects(other)
"""
--
You received this message because you are subscribed to the Google Groups
"sqlalchemy" group.
To post to this group, send email to sqlalch...@googlegroups.com.
To unsubscribe from this group, send email to
sqlalchemy+unsubscr...@googlegroups.com.
For more options, visit this group at
http://groups.google.com/group/sqlalchemy?hl=en.
