sqlalchemy：无法使用日期列保存模型

Question

我已经通过 declarative_base 创建了一个模型：

Base = declarative_base()

class Record(Base):
    __tablename__ = 'test'

    id = Column(BigInteger, primary_key=True)
    datefrom = Column(Date)
    dateto = Column(Date)
    active = Column(Boolean, index=True, default=True)
    created = Column(DateTime, default=datetime.datetime.utcnow)

当我尝试将模块保存到 postgres 数据库时：

dfrom = datetime.datetime.strptime(somestring, '%d/%m/%Y').date()
dto = datetime.datetime.strptime(someotherstring, '%d/%m/%Y').date()
record = Record(datefrom=dfrom, dateto=dto)
session.add(record)
session.commit()

我收到以下错误：

(DataError) invalid input syntax for type date: \"\"\nLINE 1: ...'2013-11-26'::date, '2013-12-27'::date...\n ^\n 'INSERT INTO test (datefrom, dateto, active, created) VALUES (%(datefrom)s, %(dateto)s, %(active)s, %(created)s) RETURNING test.id' {'created': datetime.datetime(2013, 11, 27, 20, 12, 55, 716185), 'dateto': datetime.date(2013, 12, 27), 'datefrom': datetime.date(2013, 11, 26), 'active': True}

类似的错误发生在 sqlite 后端：

SQLite Date type only accepts Python date objects as input. (original cause: TypeError: SQLite Date type only accepts Python date objects as input.) 'INSERT INTO test (datefrom, dateto, active, created) VALUES (?, ?, ?, ?)' [{'dateto': datetime.date(2013, 12, 27), 'datefrom': datetime.date(2013, 11, 26)}]

那我做错了什么？ datetime.date 对象不应该这样工作吗？

Answer 1

不是答案*，只是进一步调查的想法：

无法在 SQLite 上重现该问题。下面的独立代码运行没有问题并产生提供的输出。你在做什么不同？你能把你遇到的问题缩小到一个类似的例子，看看它有什么不同吗？ （注意：使用 SA v0.8.3）

代码：

import datetime

from sqlalchemy import *
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base

Base = declarative_base()

engine = create_engine('sqlite:///:memory:', echo=True)
Session = sessionmaker(bind=engine)

# object model
class Record(Base):
    __tablename__ = 'test'
    id = Column(Integer, primary_key=True)
    datefrom = Column(Date)
    dateto = Column(Date)
    active = Column(Boolean, index=True, default=True)
    created = Column(DateTime, default=datetime.datetime.utcnow)

# create db schema
Base.metadata.create_all(engine)
session = Session()

# TEST INSERT DATA
somestring, someotherstring = '3/1/2008', '1/3/1988'
dfrom = datetime.datetime.strptime(somestring, '%d/%m/%Y').date()
dto = datetime.datetime.strptime(someotherstring, '%d/%m/%Y').date()
record = Record(datefrom=dfrom, dateto=dto)
session.add(record)
session.commit()
session.expunge_all()

输出：

2013-11-28 09:17:14,608 INFO sqlalchemy.engine.base.Engine PRAGMA table_info("test")
2013-11-28 09:17:14,608 INFO sqlalchemy.engine.base.Engine ()
2013-11-28 09:17:14,609 INFO sqlalchemy.engine.base.Engine
CREATE TABLE test (
        id INTEGER NOT NULL,
        datefrom DATE,
        dateto DATE,
        active BOOLEAN,
        created DATETIME,
        PRIMARY KEY (id),
        CHECK (active IN (0, 1))
)


2013-11-28 09:17:14,611 INFO sqlalchemy.engine.base.Engine ()
2013-11-28 09:17:14,611 INFO sqlalchemy.engine.base.Engine COMMIT
2013-11-28 09:17:14,611 INFO sqlalchemy.engine.base.Engine CREATE INDEX ix_test_active ON test (active)
2013-11-28 09:17:14,611 INFO sqlalchemy.engine.base.Engine ()
2013-11-28 09:17:14,612 INFO sqlalchemy.engine.base.Engine COMMIT
2013-11-28 09:17:14,618 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2013-11-28 09:17:14,618 INFO sqlalchemy.engine.base.Engine INSERT INTO test (datefrom, dateto, active, created) VALUES (?, ?, ?, ?)
2013-11-28 09:17:14,618 INFO sqlalchemy.engine.base.Engine ('2008-01-03', '1988-03-01', 1, '2013-11-28 08:17:14.619000')
2013-11-28 09:17:14,619 INFO sqlalchemy.engine.base.Engine COMMIT