无法在postgresql表flasksqlalchemy中设置uuid主字段

Question

我正在创建一个后端，在postgresql数据库中，有多个表以user id为主要字段，is为UUID类型。但我得到了以下错误：

Traceback (most recent call last):
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1179, in _execute_context
    context = constructor(dialect, self, conn, *args)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/engine/default.py", line 743, in _init_compiled
    for key in compiled_params
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/engine/default.py", line 743, in <genexpr>
    for key in compiled_params
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/dialects/postgresql/psycopg2.py", line 487, in process
    value = _python_UUID(value)
  File "/usr/lib64/python3.7/uuid.py", line 157, in __init__
    hex = hex.replace('urn:', '').replace('uuid:', '')
AttributeError: 'UUID' object has no attribute 'replace'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/flask/app.py", line 1832, in full_dispatch_request
    rv = self.dispatch_request()
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/flask/app.py", line 1818, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/flask_restful/__init__.py", line 458, in wrapper
    resp = resource(*args, **kwargs)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/flask/views.py", line 88, in view
    return self.dispatch_request(*args, **kwargs)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/flask_restful/__init__.py", line 573, in dispatch_request
    resp = meth(*args, **kwargs)
  File "/mnt/home/Programming/Projects/Social Network/Server/src/new_user.py", line 17, in post
    self.database_helper(args)
  File "/mnt/home/Programming/Projects/Social Network/Server/src/new_user.py", line 26, in database_helper
    db.session.commit()
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/orm/scoping.py", line 162, in do
    return getattr(self.registry(), name)(*args, **kwargs)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 1026, in commit
    self.transaction.commit()
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 493, in commit
    self._prepare_impl()
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 472, in _prepare_impl
    self.session.flush()
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2458, in flush
    self._flush(objects)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2596, in _flush
    transaction.rollback(_capture_exception=True)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/util/langhelpers.py", line 68, in __exit__
    compat.reraise(exc_type, exc_value, exc_tb)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/util/compat.py", line 129, in reraise
    raise value
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 2556, in _flush
    flush_context.execute()
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/orm/unitofwork.py", line 422, in execute
    rec.execute(self)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/orm/unitofwork.py", line 589, in execute
    uow,
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/orm/persistence.py", line 245, in save_obj
    insert,
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/orm/persistence.py", line 1066, in _emit_insert_statements
    c = cached_connections[connection].execute(statement, multiparams)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 988, in execute
    return meth(self, multiparams, params)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/sql/elements.py", line 287, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1107, in _execute_clauseelement
    distilled_params,
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1182, in _execute_context
    e, util.text_type(statement), parameters, None, None
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1466, in _handle_dbapi_exception
    util.raise_from_cause(sqlalchemy_exception, exc_info)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/util/compat.py", line 383, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb, cause=cause)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/util/compat.py", line 128, in reraise
    raise value.with_traceback(tb)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1179, in _execute_context
    context = constructor(dialect, self, conn, *args)
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/engine/default.py", line 743, in _init_compiled
    for key in compiled_params
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/engine/default.py", line 743, in <genexpr>
    for key in compiled_params
  File "/home/ayushs/.local/share/virtualenvs/Server-D_x4HQZH/lib/python3.7/site-packages/sqlalchemy/dialects/postgresql/psycopg2.py", line 487, in process
    value = _python_UUID(value)
  File "/usr/lib64/python3.7/uuid.py", line 157, in __init__
    hex = hex.replace('urn:', '').replace('uuid:', '')
sqlalchemy.exc.StatementError: (builtins.AttributeError) 'UUID' object has no attribute 'replace'

这是我的模型：

^{pr2}$

下面是我的数据库助手函数：

def database_helper(self, args):
        id = uuid4()
        userAuth = AuthenticationModel(user_id=id, email=args['email'], phone_no=args['phone_no'], password_raw=args['password'])
        userInfo = PersonalInfoModel(user_id=id, first_name=args['first_name'], last_name=args['last_name'], dob=args['dob'])
        db.session.add(userAuth)
        db.session.add(userInfo)
        db.session.commit()

我发现了很多自动生成UUID字段的例子。但是，如果我想在多个数据库中创建一些用户，我该怎么做呢？因为我认为我需要能够将用户id传递给其他表，即使我为其中一个表自动生成它。或者我应该简单地使用一个文本字段？在

Answer 1

uuid4()正在生成一个UUID实例。在

您想为user_id字段传递一个字符串。将其转换为字符串

user_id = str(uuid4())

如果希望传递UUID实例并在结果中返回它们，则应将架构中的user_id字段更新为：

^{pr2}$