나는 postgresql 데이터베이스에서 sqlalchemy를 통해 작업 중이다. postgresql "날짜"열 유형 (BC 날짜는 http://www.postgresql.org/docs/9.2/static/datatype-datetime.html을 지원합니다)으로 BC 날짜와 함께 작업해야합니다. 그러나 BC 날짜를 문자열 형식 (예 : '2000-01-01 BC')으로 삽입 할 수는 있지만 검색 할 수는 없습니다. 데이터베이스에서 BC 날짜를 얻으려고하는 중 값 오류 : 연도가 범위를 벗어났습니다. 처음에는 그 이유가 Date 형식의 sqlalchemy가 BC 날짜를 지원하지 않는 python datetime.date 모듈을 사용한다고 생각했지만 완전히 확신하지는 않습니다. datetime.date 모듈의 사용을 피하기 위해 데이터베이스에서 "날짜"유형을 사용자 지정 파이썬 클래스에 매핑하는 방법을 찾으려고했지만 성공하지 못했습니다 (sqlalchemy의 다양한 처리 단계에 논리를 추가하는 방법을 찾았습니다. result_processor 또는 bind_expression과 같이 column_expression을 사용했지만 작동하도록 만들지는 못했습니다.)postgresql로 sqlalchemy BC 날짜
다음은 문제를 재현하는 예입니다. 트레이스
from sqlalchemy import create_engine, Column, Integer, String, Date
from sqlalchemy.orm import sessionmaker
from sqlalchemy.ext.declarative import declarative_base
engine = create_engine('postgresql://database:[email protected]:5432/sqlalchemy_test', echo=True)
Base = declarative_base()
class User(Base):
__tablename__ = 'users'
id = Column(Integer, primary_key=True)
name = Column(String)
date = Column(Date)
def __repr__(self):
return "<User(name='%s', date='%s')>" % (self.name, self.date)
Base.metadata.create_all(engine)
Session = sessionmaker(bind=engine)
session = Session()
# remove objects from previous launches
session.query(User).delete()
import datetime
a_date = datetime.date.today()
# Insert valid date in datetime.date format, it works.
ed_user = User(name='ed', date=a_date)
# Insert BC date in string format, it works.
al_user = User(name='al', date='1950-12-16 BC')
session.add_all([ed_user, al_user])
session.commit()
# Insert data via raw sql, it works
conn = engine.connect()
conn.execute('INSERT INTO users (name, date) VALUES (%s, %s)', ("Lu", "0090-04-25 BC"))
# Check that all 3 objects are present
user_names = session.query(User.name).all()
print user_names
# Check entry with AD date, it works.
user = session.query(User).filter_by(name='ed').first()
print '-- user vith valid date: ', user, user.date
# But when trying to fetch date fields in any way, it raises Value error
# Trying to fetch model, it raises Value error
users = session.query(User).all()
print users
# Trying to fetch only field, it raises Value error
user_dates = session.query(User.date).all()
print user_dates
# Even trying to fetch dates in raw sql raises Value error
a = conn.execute('SELECT * FROM users')
print [c for c in a]
그리고 출력 : 나는 PostgreSQL을 9.1.11, SQLAlchemy의 0.9.4을 사용하고
2014-06-19 16:06:20,466 INFO sqlalchemy.engine.base.Engine select version()
2014-06-19 16:06:20,466 INFO sqlalchemy.engine.base.Engine {}
2014-06-19 16:06:20,468 INFO sqlalchemy.engine.base.Engine select current_schema()
2014-06-19 16:06:20,468 INFO sqlalchemy.engine.base.Engine {}
2014-06-19 16:06:20,470 INFO sqlalchemy.engine.base.Engine SELECT CAST('test plain returns' AS VARCHAR(60)) AS anon_1
2014-06-19 16:06:20,470 INFO sqlalchemy.engine.base.Engine {}
2014-06-19 16:06:20,471 INFO sqlalchemy.engine.base.Engine SELECT CAST('test unicode returns' AS VARCHAR(60)) AS anon_1
2014-06-19 16:06:20,471 INFO sqlalchemy.engine.base.Engine {}
2014-06-19 16:06:20,473 INFO sqlalchemy.engine.base.Engine show standard_conforming_strings
2014-06-19 16:06:20,473 INFO sqlalchemy.engine.base.Engine {}
2014-06-19 16:06:20,475 INFO sqlalchemy.engine.base.Engine select relname from pg_class c join pg_namespace n on n.oid=c.relnamespace where n.nspname=current_schema() and relname=%(name)s
2014-06-19 16:06:20,475 INFO sqlalchemy.engine.base.Engine {'name': u'users'}
2014-06-19 16:06:20,477 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2014-06-19 16:06:20,478 INFO sqlalchemy.engine.base.Engine DELETE FROM users
2014-06-19 16:06:20,478 INFO sqlalchemy.engine.base.Engine {}
2014-06-19 16:06:20,480 INFO sqlalchemy.engine.base.Engine INSERT INTO users (name, date) VALUES (%(name)s, %(date)s) RETURNING users.id
2014-06-19 16:06:20,481 INFO sqlalchemy.engine.base.Engine {'date': datetime.date(2014, 6, 19), 'name': 'ed'}
2014-06-19 16:06:20,482 INFO sqlalchemy.engine.base.Engine INSERT INTO users (name, date) VALUES (%(name)s, %(date)s) RETURNING users.id
2014-06-19 16:06:20,482 INFO sqlalchemy.engine.base.Engine {'date': '1950-12-16 BC', 'name': 'al'}
2014-06-19 16:06:20,483 INFO sqlalchemy.engine.base.Engine COMMIT
2014-06-19 16:06:20,494 INFO sqlalchemy.engine.base.Engine INSERT INTO users (name, date) VALUES (%s, %s)
2014-06-19 16:06:20,494 INFO sqlalchemy.engine.base.Engine ('Lu', '0090-04-25 BC')
2014-06-19 16:06:20,495 INFO sqlalchemy.engine.base.Engine COMMIT
2014-06-19 16:06:20,517 INFO sqlalchemy.engine.base.Engine BEGIN (implicit)
2014-06-19 16:06:20,517 INFO sqlalchemy.engine.base.Engine SELECT users.name AS users_name
FROM users
2014-06-19 16:06:20,517 INFO sqlalchemy.engine.base.Engine {}
-- user names: [(u'ed',), (u'al',), (u'Lu',)]
2014-06-19 16:06:20,520 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id, users.name AS users_name, users.date AS users_date
FROM users
WHERE users.name = %(name_1)s
LIMIT %(param_1)s
2014-06-19 16:06:20,520 INFO sqlalchemy.engine.base.Engine {'name_1': 'ed', 'param_1': 1}
-- user with valid date: <User(name='ed', date='2014-06-19')> 2014-06-19
2014-06-19 16:06:20,523 INFO sqlalchemy.engine.base.Engine SELECT users.id AS users_id, users.name AS users_name, users.date AS users_date
FROM users
2014-06-19 16:06:20,523 INFO sqlalchemy.engine.base.Engine {}
Traceback (most recent call last):
File "test_script.py", line 49, in <module>
users = session.query(User).all()
File "/home/pavel/.virtualenvs/common/local/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2292, in all
return list(self)
File "/home/pavel/.virtualenvs/common/local/lib/python2.7/site-packages/sqlalchemy/orm/loading.py", line 65, in instances
fetch = cursor.fetchall()
File "/home/pavel/.virtualenvs/common/local/lib/python2.7/site-packages/sqlalchemy/engine/result.py", line 788, in fetchall
self.cursor, self.context)
File "/home/pavel/.virtualenvs/common/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1111, in _handle_dbapi_exception
util.reraise(*exc_info)
File "/home/pavel/.virtualenvs/common/local/lib/python2.7/site-packages/sqlalchemy/engine/result.py", line 782, in fetchall
l = self.process_rows(self._fetchall_impl())
File "/home/pavel/.virtualenvs/common/local/lib/python2.7/site-packages/sqlalchemy/engine/result.py", line 749, in _fetchall_impl
return self.cursor.fetchall()
ValueError: year is out of range
, 파이썬 2.7
내 질문은 : 작업하는 방법은 무엇입니까 BC는 postgresql "date"형식의 열을 sqlalchemy를 통해 열거합니다 (최소한 문자열로 검색하지만 FlexiDate 또는 astropy.time과 같은 BC 날짜를 사용할 수있는 일부 모듈에 시각적으로 매핑합니다)?