ProgrammingError在SQLAlchemy中的线程错误

Question

我在sqlite db中有两个简单的表.

from sqlalchemy import MetaData, Table, Column, Integer, ForeignKey, \
    create_engine, String
from sqlalchemy.orm import mapper, relationship, sessionmaker, scoped_session
from sqlalchemy.ext.declarative import declarative_base

engine = create_engine('sqlite:///dir_graph.sqlite', echo=True)

session_factory = sessionmaker(bind=engine)
Session = scoped_session(session_factory)
session = Session()

Base = declarative_base()

class NodeType(Base):
    __tablename__ = 'nodetype'
    id = Column(Integer, primary_key=True)
    name = Column(String(20), unique=True)
    nodes = relationship('Node', backref='nodetype')

def __init__(self, name):
    self.name = name

def __repr__(self):
    return "Nodetype: %s" % self.name


class Node(Base):
    __tablename__ = 'node'

    id = Column(Integer, primary_key=True)
    name = Column(String(20), unique=True)
    type_id = Column(Integer,
                 ForeignKey('nodetype.id'))


    def __init__(self, _name, _type_id):
        self.name = _name
        self.type_id = _type_id

Base.metadata.create_all(engine) 

在运行之后,我与解释器交互.例如,n1 = Node('Node1',1)来了解sqlalchemy.我做了一个session.commit()并尝试了另一个语句,例如n2 = Node('n2',1)我得到了这个错误:sqlalchemy.exc.ProgrammingError:(ProgrammingError)在一个线程中创建的SQLite对象只能用于相同的线程.该对象是在线程ID 3932中创建的,这是线程ID 5740无无.

我提交后如何继续会话？TNX

Answer 1

SQLite默认禁止在多个线程中使用单个连接.只需将connect_args={'check_same_thread': False}参数添加到engine变量中即可

engine = create_engine('sqlite:///dir_graph.sqlite', connect_args={'check_same_thread': False}, echo=True)