IntegrityError：错误：列“user_id”中的空值违反了非空约束

使用：postgres（PostgreSQL）9.4.5

我刚刚迁移了一个sqlite3数据库到一个postgresqlD b。由于某种原因，自从这次迁移以来，当我尝试创建用户时，出现了有关user_id（这是主键）正在被提升。以前这不是问题sqlite3。我花了时间浏览文档和堆栈问题，但仍然感到困惑。

Inside api.create_user():

api.create_user(username ='lola ', firstname ='cats ', lastname ='lcatk', email='[email protected]')

sqlalchemy 数据库 Model:

class User(Base):
    __tablename__ = 'users'

    #user_id = Column(Integer, primary_key=True)
    #changed to:
    id = Column(Integer, primary_key=True)
    username = Column(String(50))
    firstname = Column(String(50))
    lastname = Column(String(50))
    email = Column(String(300))
    password = Column(String(12))
    institution = Column(String(50))

    def __init__(self, username, firstname, lastname, email):
        self.username = username
        self.firstname = firstname
        self.lastname = lastname
        self.email = email

    def __repr__(self):
        return "<User(username ='%s', firstname ='%s', lastname ='%s', email='%s')>" % (self.username, self.firstname, self.lastname, self.email)

pyramid视图.py：

@view_config(#code supplying the template and etc.)
def save_assessment_result(request):
    with transaction.manager:
        username = request.params['username']
        firstname = request.params['firstname']
        lastname = request.params['lastname']
        email = request.params['email']
        user = api.create_user(username, firstname, lastname, email)
        #mode code to commit and etc.
    transaction.commit()
    return HTTPCreated()

postgres服务器日志：

ERROR:  null value in column "user_id" violates not-null constraint
DETAIL:  Failing row contains (null, lola , cats , lcatk, [email protected], null, null, 2015-10-19 23:02:21.560395).
STATEMENT:  INSERT INTO users (username, firstname, lastname, email, password, institution, created_on) VALUES ('lola ', 'cats ', 'lcatk', '[email protected]', NULL, NULL, '2015-10-19T23:02:21.560395'::timestamp) RETURNING users.user_id

追溯:

015-10-19 19:02:21,563 ERROR [pyramid_debugtoolbar][Dummy-3] Exception at http://0.0.0.0:6432/save_assessment_result
  File "/Users/ack/code/venv/NotssWEB/notssweb/views/default.py", line 61, in save_assessment_result
    assessment = api.retrieve_assessment(assessment_id)
  File "/usr/local/lib/python2.7/site-packages/notssdb/api/object.py", line 112, in retrieve_assessment
    filter(Assessment.assessment_id == something_unique).one()
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2473, in one
    ret = list(self)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/query.py", line 2515, in __iter__
    self.session._autoflush()
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 1292, in _autoflush
    util.raise_from_cause(e)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/util/compat.py", line 199, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 1282, in _autoflush
    self.flush()
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 2004, in flush
    self._flush(objects)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 2122, in _flush
    transaction.rollback(_capture_exception=True)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/util/langhelpers.py", line 60, in __exit__
    compat.reraise(exc_type, exc_value, exc_tb)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/session.py", line 2086, in _flush
    flush_context.execute()
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/unitofwork.py", line 373, in execute
    rec.execute(self)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/unitofwork.py", line 532, in execute
    uow
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/persistence.py", line 174, in save_obj
    mapper, table, insert)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/orm/persistence.py", line 781, in _emit_insert_statements
    execute(statement, params)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 914, in execute
    return meth(self, multiparams, params)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/sql/elements.py", line 323, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1010, in _execute_clauseelement
    compiled_sql, distilled_params
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1146, in _execute_context
    context)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1341, in _handle_dbapi_exception
    exc_info
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/util/compat.py", line 199, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/engine/base.py", line 1139, in _execute_context
    context)
  File "/usr/local/lib/python2.7/site-packages/sqlalchemy/engine/default.py", line 450, in do_execute
    cursor.execute(statement, parameters)
IntegrityError: (raised as a result of Query-invoked autoflush; consider using a session.no_autoflush block if this flush is occurring prematurely) (psycopg2.IntegrityError) null value in column "user_id" violates not-null constraint
DETAIL:  Failing row contains (null, lola , cats , lcatk, [email protected], null, null, 2015-10-19 23:02:21.560395).
 [SQL: 'INSERT INTO users (username, firstname, lastname, email, password, institution, created_on) VALUES (%(username)s, %(firstname)s, %(lastname)s, %(email)s, %(password)s, %(institution)s, %(created_on)s) RETURNING users.user_id'] [parameters: {'username': u'lola ', 'firstname': u'cats ', 'lastname': u'lcatk', 'institution': None, 'created_on': datetime.datetime(2015, 10, 19, 23, 2, 21, 560395), 'password': None, 'email': u'[email protected]'}]
2015-10-19 19:02:21,564 DEBUG [notssweb][Dummy-3] route matched for url http://0.0.0.0:6432/_debug_toolbar/exception?token=a30c0989db02aeff9cd2&tb=4459323984; route_name: 'debugtoolbar', path_info: u'/_debug_toolbar/exception', pattern: '/_debug_toolbar/*subpath', matchdict: {'subpath': (u'exception',)}, predicates: '

First.
我更改了 id 命名约定user_id简单地id在数据库中（这对于所有其他数据库都是如此）。

class User(Base):
    __tablename__ = 'users'

    id = Column(Integer, primary_key=True)

Second.
该问题是在将原始 sqlite 数据库文件转储到 postgres 中（从 sqlite3 --> postgres）而不是在 postgres 中创建数据库时发现的。
因此，我在 SQLAlchemy 中运行原始代码，但这次指向 postgres 数据库：

engine = create_engine('postgresql://localhost/some_db')

这创建了所需的关系和序列（通过\ds在 postgres 中，psql）。问题解决了。