Question

我正在按照本教程关于在Postgres http://newcoder.io/scrape中使用Scrapy。我是postgres的新手，非常熟悉scrapy。

在教程中没有任何地方说明有关迁移的内容，因此我认为它打算使用DeclarativeBase.metadata.create_all(engine)或代码内容在某处生成表。

我的models.py

from sqlalchemy import Table, create_engine, Column, Integer, String, DateTime
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.engine.url import URL

import settings


DeclarativeBase = declarative_base()


def db_connect():
    return create_engine(URL(**settings.DATABASE))

def create_scores_table(engine):
    """"""
    DeclarativeBase.metadata.create_all(engine)

class Scores(DeclarativeBase):
        __tablename__ = "scores"

        id = Column(Integer, primary_key=True)
        score = Column('score', String, nullable=True)

我的pipelines.py：

from sqlalchemy.orm import sessionmaker
from models import Scores, db_connect, create_scores_table

class RrsportsPipeline(object):

def __init__(self):

    engine = db_connect()
    create_scores_table(engine)
    self.Session = sessionmaker(bind=engine)


def process_item(self, item, spider):
    session = self.Session()
    scores = Scores(**item)
    try:
        session.add(scores)
        session.commit()
    except:
        session.rollback()
        raise
    finally:
        session.close()
    return item

我知道数据库也正确连接了正确的信用卡和数据库名称。

完整的追踪

Traceback (most recent call last):
  File "/usr/local/lib/python2.7/dist-packages/twisted/internet/defer.py", line 588, in _runCallbacks
    current.result = callback(current.result, *args, **kw)
  File "/home/ubuntu/rgsports/rgsports/rgsports/pipelines.py", line 44, in process_item
    session.commit()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 801, in commit
    self.transaction.commit()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 392, in commit
    self._prepare_impl()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 372, in _prepare_impl
    self.session.flush()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 2019, in flush
    self._flush(objects)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 2137, in _flush
    transaction.rollback(_capture_exception=True)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/langhelpers.py", line 60, in __exit__
    compat.reraise(exc_type, exc_value, exc_tb)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 2101, in _flush
    flush_context.execute()
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/unitofwork.py", line 373, in execute
    rec.execute(self)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/unitofwork.py", line 532, in execute
    uow
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/persistence.py", line 174, in save_obj
    mapper, table, insert)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/persistence.py", line 800, in _emit_insert_statements
    execute(statement, params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 914, in execute
    return meth(self, multiparams, params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/elements.py", line 323, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1010, in _execute_clauseelement
    compiled_sql, distilled_params
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1146, in _execute_context
    context)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1341, in _handle_dbapi_exception
    exc_info
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/compat.py", line 202, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb, cause=cause)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1139, in _execute_context
    context)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 450, in do_execute
    cursor.execute(statement, parameters)
ProgrammingError: (psycopg2.ProgrammingError) column "score" of relation "scores" does not exist

LINE 1: INSERT INTO scores (score)
                               ^
 [SQL: 'INSERT INTO scores (score) VALUES (%(score)s) RETURNING scores.id'] [parameters: {'score': u'114'}]

但是当我跑蜘蛛时：

ProgrammingError: column "score" of relation "scores" does not exist

我应该手动创建表格吗？如果是这样，怎么样？我更喜欢在代码中使用它。我的模特中有什么东西我不见了吗？或者我是否必须将模型作为某种故意迁移运行？我似乎无法触发要构建的表。

Answer 1

在pipeline.py中，您似乎需要导入create_scores_table而不是create_matchups_table

它的内容如下：

string msg = "word by word\n this is test";
string eachWord;
while( // something here ) {
    // do some code here to get word by word
    // but it should get white space and new line when it hits them
}

应为：

from sqlalchemy.orm import sessionmaker
from models import Scores, db_connect, create_matchups_table

ProgrammingError：关系“schema”的列“column”不存在

1 个答案: