Question

更新

@datetime_as_timestamp.expression
def datetime_as_timestamp(cls):
    return db.func.timestamp(cls.date, cls.time)

到

@datetime_as_timestamp.expression
def datetime_as_timestamp(cls):
    return cls.date + cls.time

原始

我的模特中有日期和时间。在另一个表中有他们的时区，但为简单起见，我将手动完成。我想按日期+时间+时区进行过滤。

class Foo(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    date = db.Column(db.Date)
    time = db.Column(db.Time)

    @hybrid_property
    def datetime_as_timestamp(self):
        return time.mktime(
            datetime.datetime.combine(self.date, self.time).timetuple()
        )

    @datetime_as_timestamp.expression
    def datetime_as_timestamp(cls):
        return db.func.timestamp(cls.date, cls.time)

但是当我执行过滤查询时

In [1]: Foo.query.filter(func.timezone('Australia/Brisbane', Foo.datetime_as_timestamp) <= func.timezone('UTC', func.current_timestamp())).one()

我收到错误

psycopg2.ProgrammingError) syntax error at or near "foo"
LINE 3: WHERE timezone('Australia/Brisbane', timestamp(foo.da...
                                                  ^
 [SQL: 'SELECT foo.id AS checkin_flight_id, foo.date AS checkin_flight_date, foo.time AS checkin_flight_time \nFROM foo \nWHERE timezone(%(timezone_1)s, timestamp(foo.date, foo.time)) <= timezone(%(timezone_2)s, CURRENT_TIMESTAMP)'] [parameters: {'timezone_2': 'UTC', 'timezone_1': 'Australia/Brisbane'}]

我错过了什么，我的错误在哪里？是否有可能以另一种方式解决我的问题？

Answer 1

我发现这个Q&A非常有帮助。我改变了

@datetime_as_timestamp.expression
def datetime_as_timestamp(cls):
    return db.func.timestamp(cls.date, cls.time)

到

@datetime_as_timestamp.expression
def datetime_as_timestamp(cls):
    return cls.date + cls.time

一切正常

SQLAlchemy按日期和时间与时区进行筛选

1 个答案: