在sqlalchemy中使用DATEADD

Question

如何在python中使用sqlalchemy重写以下sql语句.我一直在寻找30分钟,但仍然找不到任何解决方案.

DATEADD(NOW(), INTERVAL 1 DAY)

要么

INSERT INTO dates (expire)
VALUES(DATEADD(NOW(), INTERVAL 1 DAY))

提前致谢

Answer 1

为了完整起见,以下是使用sqlalchemy.sql.func以下方法生成精确SQL的方法:

from sqlalchemy.sql import func
from sqlalchemy.sql.expression import bindparam
from sqlalchemy import Interval

tomorrow = func.dateadd(func.now(), bindparam('tomorrow', timedelta(days=1), Interval()))

这导致:

>>> from sqlalchemy.sql import func
>>> func.dateadd(func.now(), bindparam('tomorrow', timedelta(days=1), Interval(native=True)))
<sqlalchemy.sql.expression.Function at 0x100f559d0; dateadd>
>>> str(func.dateadd(func.now(), bindparam('tomorrow', timedelta(days=1), Interval(native=True))))
'dateadd(now(), :tomorrow)'

或者,您可以使用text()对象来指定间隔:

from sqlalchemy.sql import func
from sqlalchemy.sql.expression import text

tomorrow = func.dateadd(func.now(), text('interval 1 day'))

Answer 2

SQLAlchemy日期自动映射到Python日期时间对象,因此您应该能够:

from sqlalchemy import Table, Column, MetaData, DateTime
from datetime import datetime, timedelta

metadata = MetaData()
example = Table('users', metadata,
   Column('expire', DateTime)
)

tomorrow = datetime.now() + timedelta(days=1)

ins = example.insert().values(expire=tomorrow)