Python：werkzeug.exceptions.InternalServerError：500 内部服务器错误：'NoneType' object 不可迭代

Question

I've seen many solutions about this problem but any of them solved mine.

I've this INSERT query which is wrapped in a try/except and, although it works fine in the database (the data is properly inserted), a Traceback is called, the code jumps to the except and the code below the query execution is just ignored (which cannnot happen in my case).

It is something like this:

query = """
  INSERT INTO
    mytable(user_id, tcx_extension, user_email, created_date)
  VALUES
    {}
""".format("('12345678910', '6666', 'test123@test.com', '2020/01/06 00:00:00')")

self.pgsql.execute_query(query)  // the error is triggered here

//important code below that is ignored when the error fires

the self.pgsql.execute_query function is shown below:

def execute_query(self, query, retry=0, format=True):
    if self.pool is None:
        self._open_pool(PGSQL["connection_string"])

    try:
        conn = self.pool.getconn()

        cur = conn.cursor()
        conn.autocommit = True

        LOG.info("Executing query", extra={"query": query})
        cur.execute(query)

        if format is True:
            data = Formatter.format_cursor(cur)
        else:
            data = None
        self.pool.putconn(conn)
        cur.close()

   except pool.PoolError as e:
        LOG.error("PoolError: {}".format(e), extra={"query": query})
        if retry > MAX_RETRIES:
            raise TooManyRetries("Too many retries: {}".format(e))

        LOG.info("Will retry: {}".format(e), extra={"query": query})
        time.sleep(1)
        return self.execute_query(query, retry + 1)

    return data

The Traceback is shown below:

[2021-01-06 15:28:15,421] ERROR in app: Exception on /members/manage_socket_members [POST]
Traceback (most recent call last):
  File "C:\Users\artur.santos\AppData\Local\Programs\Python\Python37\lib\site-packages\flask\app.py", line 1612, in full_dispatch_request
    rv = self.dispatch_request()
  File "C:\Users\artur.santos\AppData\Local\Programs\Python\Python37\lib\site-packages\flask\app.py", line 1598, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "C:\Users\artur.santos\AppData\Local\Programs\Python\Python37\lib\site-packages\flask_restful\__init__.py", line 480, in wrapper
    resp = resource(*args, **kwargs)
  File "C:\Users\artur.santos\AppData\Local\Programs\Python\Python37\lib\site-packages\flask\views.py", line 84, in view
    return self.dispatch_request(*args, **kwargs)
  File "C:\Users\artur.santos\AppData\Local\Programs\Python\Python37\lib\site-packages\flask_restful\__init__.py", line 595, in dispatch_request
    resp = meth(*args, **kwargs)
  File "C:\Users\artur.santos\Documents\#salesforce\rc-analytics-api\src\decorators\auth.py", line 70, in wrap
    return f(*args, **kwargs)
  File "C:\Users\artur.santos\Documents\#salesforce\rc-analytics-api\src\members\manage_socket_members.py", line 30, in post
    return abort(500, error)
  File "C:\Users\artur.santos\AppData\Local\Programs\Python\Python37\lib\site-packages\werkzeug\exceptions.py", line 707, in abort
    return _aborter(status, *args, **kwargs)
  File "C:\Users\artur.santos\AppData\Local\Programs\Python\Python37\lib\site-packages\werkzeug\exceptions.py", line 687, in __call__
    raise self.mapping[code](*args, **kwargs)
werkzeug.exceptions.InternalServerError: 500 Internal Server Error: 'NoneType' object is not iterable

Any ideas on how to solve this?

EDIT 1: All the table fields are of type 'VARCHAR' except for the created_date .

EDIT 2: When I try to insert some values between double quotes the error changes (which is also a nonsense error for me). I don't know if gets me closer to the solution. Check it out the logs I printed

> query: INSERT INTO wfm.socket_user_relation (user_id, tcx_extension, user_email, created_date) VALUES (12345678937, 63, "test37@test.com.br", "2021/01/07 09:25:35")
> exception: column "test37@test.com.br" does not exist
LINE 1: ...ser_email, created_date) VALUES (12345678937, 63, "test37@te...
                                                             ^

EDIT 3: If I try to INSERT all of them double quoted, the error remains the same: Error: 500 Internal Server Error: 'NoneType' object is not iterable

Answer 1

You are not setting the format parameter when executing the function and therefore it's always True (as you stablished in the function definition).

The response when you successfully insert something in the PgSQL DB is None and it's not possible to String format a NoneType Object .

Just use the code above and you will be fine.

self.pgsql.execute_query(query, format=False).