Issue around connecting to a MySQL database table - python

I have some code which tries to connect to a mySQL database and retrieve a query.
The connection code is in a module called connection and looks like:
#!/usr/bin/env python3
import pandas as pd
import pymysql
from sqlalchemy import create_engine
COMPANY_SERVER = create_engine(
'mysql+pymysql://view_user:connectiondetails')
def read_sql(query):
return pd.read_sql_query(query, COMPANY_SERVER)
I have omitted the connection details for security. But this connection has worked in the past.
I am trying to connect and query a database table (which is pulled in with variable name table) and trying returning a DESCRIBE of the table in the following way:
#!/usr/bin/env python3
import datetime as dt
import numpy as np
import pandas as pd
from copy import copy
import pymysql
from sql.connection import read_sql
class DBSnapData(object):
def __init__(self,
start_dt,
end_dt,
start_point,
end_point,
variables,
table,
stock_id
):
self.start_dt = start_dt
self.end_dt = end_dt
self.start_point = start_point
self.end_point = end_point
self.variables = variables
self.table = table
self.stock_id = stock_id
self.schema = self.load_schema()
def load_schema(self):
return run_schema_sql_query(self.table)
def run_schema_sql_query(table):
return read_sql('DESCRIBE %s' % table)
I am getting the following error output:
2018-01-17 22:34:02,717 (pymysql.err.OperationalError) (1142, "SELECT command denied to user 'view_user'#'192.168.9.132' for table 'TBL_MKTDATA_SNAPS_AUS'") [SQL: 'DESCRIBE TBL_MKTDATA_SNAPS_AUS']
Traceback (most recent call last):
File "/usr/local/lib64/python3.5/site-packages/sqlalchemy/engine/base.py", line 1182, in _execute_context
context)
File "/usr/local/lib64/python3.5/site-packages/sqlalchemy/engine/default.py", line 470, in do_execute
cursor.execute(statement, parameters)
File "/usr/local/lib/python3.5/site-packages/pymysql/cursors.py", line 166, in execute
result = self._query(query)
File "/usr/local/lib/python3.5/site-packages/pymysql/cursors.py", line 322, in _query
conn.query(q)
File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 856, in query
self._affected_rows = self._read_query_result(unbuffered=unbuffered)
File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 1057, in _read_query_result
result.read()
File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 1340, in read
first_packet = self.connection._read_packet()
File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 1014, in _read_packet
packet.check_error()
File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 393, in check_error
err.raise_mysql_exception(self._data)
File "/usr/local/lib/python3.5/site-packages/pymysql/err.py", line 107, in raise_mysql_exception
raise errorclass(errno, errval)
pymysql.err.OperationalError: (1142, "SELECT command denied to user 'view_user'#'192.168.9.132' for table 'TBL_MKTDATA_SNAPS_AUS'")
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/home/scoleman/bin/export_mkt_data", line 405, in main
extract_by_id(sc_id, bbg_ticker, bb_id, lot_size_changes)
File "/home/scoleman/bin/export_mkt_data", line 346, in extract_by_id
stock_id)
File "/home/scoleman/git/sql_data/sx_data_adhoc.py", line 100, in __init__
self.schema = self.load_schema()
File "/home/scoleman/git/sql_data/sx_data_adhoc.py", line 106, in load_schema
return run_schema_sql_query(self.table)
File "/home/scoleman/git/sql_data/sx_data_adhoc.py", line 19, in run_schema_sql_query
return read_sql('DESCRIBE %s' % table)
File "/home/scoleman/git/sql_data/sql/connection.py", line 17, in read_sql
return pd.read_sql_query(query, COMPANY_SERVER)
File "/usr/local/lib64/python3.5/site-packages/pandas/io/sql.py", line 331, in read_sql_query
parse_dates=parse_dates, chunksize=chunksize)
File "/usr/local/lib64/python3.5/site-packages/pandas/io/sql.py", line 1084, in read_query
result = self.execute(*args)
File "/usr/local/lib64/python3.5/site-packages/pandas/io/sql.py", line 975, in execute
return self.connectable.execute(*args, **kwargs)
File "/usr/local/lib64/python3.5/site-packages/sqlalchemy/engine/base.py", line 2064, in execute
return connection.execute(statement, *multiparams, **params)
File "/usr/local/lib64/python3.5/site-packages/sqlalchemy/engine/base.py", line 939, in execute
return self._execute_text(object, multiparams, params)
File "/usr/local/lib64/python3.5/site-packages/sqlalchemy/engine/base.py", line 1097, in _execute_text
statement, parameters
File "/usr/local/lib64/python3.5/site-packages/sqlalchemy/engine/base.py", line 1189, in _execute_context
context)
File "/usr/local/lib64/python3.5/site-packages/sqlalchemy/engine/base.py", line 1402, in _handle_dbapi_exception
exc_info
File "/usr/local/lib64/python3.5/site-packages/sqlalchemy/util/compat.py", line 203, in raise_from_cause
reraise(type(exception), exception, tb=exc_tb, cause=cause)
File "/usr/local/lib64/python3.5/site-packages/sqlalchemy/util/compat.py", line 186, in reraise
raise value.with_traceback(tb)
File "/usr/local/lib64/python3.5/site-packages/sqlalchemy/engine/base.py", line 1182, in _execute_context
context)
File "/usr/local/lib64/python3.5/site-packages/sqlalchemy/engine/default.py", line 470, in do_execute
cursor.execute(statement, parameters)
File "/usr/local/lib/python3.5/site-packages/pymysql/cursors.py", line 166, in execute
result = self._query(query)
File "/usr/local/lib/python3.5/site-packages/pymysql/cursors.py", line 322, in _query
conn.query(q)
File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 856, in query
self._affected_rows = self._read_query_result(unbuffered=unbuffered)
File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 1057, in _read_query_result
result.read()
File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 1340, in read
first_packet = self.connection._read_packet()
File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 1014, in _read_packet
packet.check_error()
File "/usr/local/lib/python3.5/site-packages/pymysql/connections.py", line 393, in check_error
err.raise_mysql_exception(self._data)
File "/usr/local/lib/python3.5/sit
If anyone could give me a pointer as to a solution it would be much appreciated. I think the problem might be with pymysql in the connection but really am unsure.
Thanks

Your error says view_user doesn't have permission to query data on 192.168.9.132 this server.
You will have to do
GRANT SELECT ON *.* TO 'view_user'#'host_or_wildcard' IDENTIFIED BY 'password'; to allow your user to query on specified server.
Or
GRANT ALL PRIVILEGES ON *.* TO 'view_user'#'192.168.9.132'; to grant all priviliges.
P.S. To do above you will have to be root user. Use mysql -u root -p command to connect to mysql server.

Related

SQLAlchemy - Broken Pipe ERROR when trying to store large BLOB (i.e. machine learning model) to MySQL database

I would like to serialize many Gensim library Word2Vec models in MySQL database. For the purpose of my project I am utilizing: Python, Flask, SQLAlchemy, and MySQL+PyMySQL. Below you can see my Word2VecModel class which I am using in order to create word2vec table in MySQL DB:
from db.db import db
import db_models.influencer
class Word2VecModel(db.Model):
__tablename__ = "word2vec"
m_id = db.Column(db.Integer, primary_key=True)
m_username = db.Column(db.String(20), db.ForeignKey("influencer.m_username"))
m_binary = db.Column(db.LargeBinary)
influencer = db.relationship("InfluencerModel")
def __init__(self, m_binary, m_username):
self.m_binary = m_binary
self.m_username = m_username
def __repr__(self):
return '<Word2Vec {}>'.format(self.m_name)
#classmethod
def find_by_username(cls, m_username):
return cls.query.filter_by(name=m_username).first()
def save_to_db(self):
db.session.add(self)
db.session.commit()
def delete_from_db(self):
db.session.delete(self)
db.session.commit()
Whenever I try to execute:
word2vec_model = Word2VecModel(pickle.dumps(word2vec), username)
word2vec_model .save_to_db()
I get the following error message:
Traceback (most recent call last):
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/connections.py", line 705, in _write_bytes
self._sock.sendall(data)
BrokenPipeError: [Errno 32] Broken pipe
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1278, in _execute_context
cursor, statement, parameters, context
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/engine/default.py", line 593, in do_execute
cursor.execute(statement, parameters)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/cursors.py", line 163, in execute
result = self._query(query)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/cursors.py", line 321, in _query
conn.query(q)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/connections.py", line 504, in query
self._execute_command(COMMAND.COM_QUERY, sql)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/connections.py", line 773, in _execute_command
self.write_packet(sql[:packet_size])
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/connections.py", line 634, in write_packet
self._write_bytes(data)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/connections.py", line 710, in _write_bytes
"MySQL server has gone away (%r)" % (e,))
pymysql.err.OperationalError: (2006, "MySQL server has gone away (BrokenPipeError(32, 'Broken pipe'))")
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "app.py", line 117, in <module>
word2vec.save_to_db()
File "/home/stefan/PycharmProjects/NLP - Influencer Text Analysis/src/flask_api/db_models/word2vec.py", line 25, in save_to_db
db.session.commit()
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/orm/scoping.py", line 163, in do
return getattr(self.registry(), name)(*args, **kwargs)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 1042, in commit
self.transaction.commit()
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 504, in commit
self._prepare_impl()
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 483, in _prepare_impl
self.session.flush()
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 2523, in flush
self._flush(objects)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 2664, in _flush
transaction.rollback(_capture_exception=True)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/util/langhelpers.py", line 69, in __exit__
exc_value, with_traceback=exc_tb,
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/util/compat.py", line 178, in raise_
raise exception
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/orm/session.py", line 2624, in _flush
flush_context.execute()
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/orm/unitofwork.py", line 422, in execute
rec.execute(self)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/orm/unitofwork.py", line 589, in execute
uow,
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/orm/persistence.py", line 245, in save_obj
insert,
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/orm/persistence.py", line 1136, in _emit_insert_statements
statement, params
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1014, in execute
return meth(self, multiparams, params)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/sql/elements.py", line 298, in _execute_on_connection
return connection._execute_clauseelement(self, multiparams, params)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1133, in _execute_clauseelement
distilled_params,
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1318, in _execute_context
e, statement, parameters, cursor, context
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1512, in _handle_dbapi_exception
sqlalchemy_exception, with_traceback=exc_info[2], from_=e
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/util/compat.py", line 178, in raise_
raise exception
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/engine/base.py", line 1278, in _execute_context
cursor, statement, parameters, context
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/sqlalchemy/engine/default.py", line 593, in do_execute
cursor.execute(statement, parameters)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/cursors.py", line 163, in execute
result = self._query(query)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/cursors.py", line 321, in _query
conn.query(q)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/connections.py", line 504, in query
self._execute_command(COMMAND.COM_QUERY, sql)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/connections.py", line 773, in _execute_command
self.write_packet(sql[:packet_size])
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/connections.py", line 634, in write_packet
self._write_bytes(data)
File "/home/stefan/.virtualenvs/dl4cv/lib/python3.6/site-packages/pymysql/connections.py", line 710, in _write_bytes
"MySQL server has gone away (%r)" % (e,))
Killed
I've read somewhere that increasing MySQL connection timeout might help, but not in my case. Here is my DB engine configuration:
app.config['SQLALCHEMY_TRACK_MODIFICATIONS'] = False
app.config['SQLALCHEMY_DATABASE_URI'] = 'mysql+pymysql://root:''#localhost/********'
app.config['PROPAGATE_EXCEPTIONS'] = True
app.config["SQLALCHEMY_ENGINE_OPTIONS"] = {"pool_recycle": 120}

Sqlalchemy issue with Azure SQL Database

I'm trying to connect to an Azure SQL Server via SQLAchemy (1.2.5), but I'm getting the following error regardless of the driver that I use:
Traceback (most recent call last):
File "C:\Users\user1\Desktop\test.py", line 27, in <module>
res = engine.connect().execute(q)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 2102, in connect
return self._connection_cls(self, **kwargs)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 90, in __init__
if connection is not None else engine.raw_connection()
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 2188, in raw_connection
self.pool.unique_connection, _connection)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 2162, in _wrap_pool_connect
e, dialect, self)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 1476, in _handle_dbapi_exception_noconnection
exc_info
File "C:\Python27\lib\site-packages\sqlalchemy\util\compat.py", line 203, in raise_from_cause
reraise(type(exception), exception, tb=exc_tb, cause=cause)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\base.py", line 2158, in _wrap_pool_connect
return fn()
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 345, in unique_connection
return _ConnectionFairy._checkout(self)
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 784, in _checkout
fairy = _ConnectionRecord.checkout(pool)
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 532, in checkout
rec = pool._do_get()
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 1189, in _do_get
self._dec_overflow()
File "C:\Python27\lib\site-packages\sqlalchemy\util\langhelpers.py", line 66, in __exit__
compat.reraise(exc_type, exc_value, exc_tb)
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 1186, in _do_get
return self._create_connection()
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 350, in _create_connection
return _ConnectionRecord(self)
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 477, in __init__
self.__connect(first_connect_check=True)
File "C:\Python27\lib\site-packages\sqlalchemy\pool.py", line 677, in __connect
exec_once(self.connection, self)
File "C:\Python27\lib\site-packages\sqlalchemy\event\attr.py", line 274, in exec_once
self(*args, **kw)
File "C:\Python27\lib\site-packages\sqlalchemy\event\attr.py", line 284, in __call__
fn(*args, **kw)
File "C:\Python27\lib\site-packages\sqlalchemy\util\langhelpers.py", line 1334, in go
return once_fn(*arg, **kw)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\strategies.py", line 183, in first_connect
dialect.initialize(c)
File "C:\Python27\lib\site-packages\sqlalchemy\dialects\mssql\base.py", line 1931, in initialize
super(MSDialect, self).initialize(connection)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\default.py", line 283, in initialize
self.do_rollback(connection.connection)
File "C:\Python27\lib\site-packages\sqlalchemy\engine\default.py", line 457, in do_rollback
dbapi_connection.rollback()
sqlalchemy.exc.ProgrammingError: (pyodbc.ProgrammingError) ('42000', '[42000] [Microsoft][ODBC Driver 13 for SQL Server][SQL Server]111214;An attempt to complete a transaction has failed. No corresponding transaction found. (111214) (SQLEndTran)') (Background on this error at: http://sqlalche.me/e/f405)
This is the script which I use to try and read a table which generates the error:
from sqlalchemy import *
from datetime import datetime
import urllib, sqlalchemy
from urllib import quote_plus as urlquote
q = """
SELECT count(*) FROM [Products]
"""
params = urllib.quote_plus("Driver={ODBC Driver 13 for SQL Server};Server=mydb.database.windows.net,1433;Database=mydb;Uid=myuser;Pwd=mypwd;Encrypt=yes;TrustServerCertificate=no;Connection Timeout=30;")
engine = sqlalchemy.engine.create_engine("mssql+pyodbc:///?odbc_connect=%s" % params)
#engine = create_engine("mssql+pyodbc://myuser:mypwd#mydb.database.windows.net/mydb?charset=utf8&driver=ODBC+Driver+13+for+SQL+Server")
print engine
res = engine.connect().execute(q)
If I run the same query directly via pyodbc, everythin works fine:
import pyodbc
cnxn = pyodbc.connect("Driver={ODBC Driver 13 for SQL Server};Server=mydb.database.windows.net,1433;Database=mydb;Uid=myuser;Pwd=mypwd;Encrypt=yes;TrustServerCertificate=no;Connection Timeout=30;")
cursor = cnxn.cursor()
cursor.execute(q)
row = cursor.fetchone()
if row:
print row
The output, in this case, is this (the table is empty):
(0, )
Can anyone help me out on this?
Please try use Driver={SQL Server} instead of Driver={ODBC Driver 13 for SQL Server}. It works fine at my side with python 2.7.
import urllib
import pyodbc
from sqlalchemy import *
q = """
SELECT count(*) FROM test
"""
params = urllib.quote_plus("Driver={SQL Server};Server=tcp:your_server_name.database.windows.net,1433;Database=your_db;Uid=xxxx;Pwd=xxxx;Encrypt=yes;TrustServerCertificate=no;Connection Timeout=30;")
engine = create_engine("mssql+pyodbc:///?odbc_connect=%s" % params)
print engine
res = engine.connect().execute(q)
print(res.fetchone())
Test result(I can fetch the result from azure sql):

sqlalchemy fails to connect to ms sql server

Trying to connect to SQL server using SQLAlchemy with pyodbc(freeTDS) as the driver; The connections succeeds if I use pyodbc directly:
>>> import pyodbc
>>> conn = pyodbc.connect('DSN=serverdsn;UID=user;PWD=password')
>>> crsr = conn.cursor()
>>> rows = crsr.execute("select ##VERSION").fetchall()
>>> print(rows)
[('Microsoft Azure SQL Data Warehouse - 10.0.9248.28 Sep 12 2017 01:08:55 Copyright (c) Microsoft Corporation', )]
>>> crsr.close()
>>> conn.close()
But when I use SQLAlchemy, it fails with a mysterious error:
>>> from sqlalchemy import create_engine
>>> e = create_engine("mssql+pyodbc://user:password#serverdsn")
>>> with e.connect() as con:
... rs = con.execute('select * from users')
... for row in rs:
... print(row)
...
Here is the full stack trace:
Traceback (most recent call last): File
"/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/pool.py",
line 1122, in _do_get
return self._pool.get(wait, self._timeout) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/util/queue.py",
line 145, in get
raise Empty sqlalchemy.util.queue.Empty
During handling of the above exception, another exception occurred:
Traceback (most recent call last): File "", line 1, in
File
"/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/engine/base.py",
line 2091, in connect
return self._connection_cls(self, **kwargs) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/engine/base.py",
line 90, in init
if connection is not None else engine.raw_connection() File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/engine/base.py",
line 2177, in raw_connection
self.pool.unique_connection, _connection) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/engine/base.py",
line 2147, in _wrap_pool_connect
return fn() File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/pool.py",
line 328, in unique_connection
return _ConnectionFairy._checkout(self) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/pool.py",
line 766, in _checkout
fairy = _ConnectionRecord.checkout(pool) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/pool.py",
line 516, in checkout
rec = pool._do_get() File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/pool.py",
line 1138, in _do_get
self._dec_overflow() File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/util/langhelpers.py",
line 66, in exit
compat.reraise(exc_type, exc_value, exc_tb) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/util/compat.py",
line 187, in reraise
raise value File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/pool.py",
line 1135, in _do_get
return self._create_connection() File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/pool.py",
line 333, in _create_connection
return _ConnectionRecord(self) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/pool.py",
line 461, in init
self.connect(first_connect_check=True) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/pool.py",
line 661, in __connect
exec_once(self.connection, self) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/event/attr.py",
line 246, in exec_once
self(*args, **kw) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/event/attr.py",
line 256, in __call
fn(*args, **kw) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/util/langhelpers.py",
line 1331, in go
return once_fn(*arg, **kw) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/engine/strategies.py",
line 181, in first_connect
dialect.initialize(c) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/connectors/pyodbc.py",
line 165, in initialize
super(PyODBCConnector, self).initialize(connection) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/dialects/mssql/base.py",
line 1742, in initialize
super(MSDialect, self).initialize(connection) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/engine/default.py",
line 256, in initialize
self.get_isolation_level(connection.connection) File "/Users/purecarscomputer/anaconda/envs/tensorflow/lib/python3.5/site-packages/sqlalchemy/dialects/mssql/base.py",
line 1735, in get_isolation_level
"tried views: %s; final error was: %s" % (views, err)) UnboundLocalError: local variable 'err' referenced before assignment
I've tried install and uninstall sqlalchemy and searched around on google, but not find a solution. Does anyone have similar problems and have a clue about what is happening?
OS information:
ProductName: Mac OS X
ProductVersion: 10.12.6
BuildVersion: 16G29
Here's the connection string I used to solve a connection problem with similar symptoms:
import urllib
from sqlalchemy import create_engine
# utilize existing odbc connection to create engine
params = urllib.quote_plus("DRIVER={}; SERVER=server; Database=database; UID=user; PWD=pw")
engine = create_engine("mssql+pyodbc:///?odbc_connect=%s" % params)
ref http://docs.sqlalchemy.org/en/latest/dialects/mssql.html#pass-through-exact-pyodbc-string

Mixing of sqlalchemy and flask-sqlalchemy sessions

The issue I am having is with the mixing of sqlalchemy sessions with flask-sqlalchemy session. So for context, I am running a flask-restful app on the background and I have a file (runnable.py) with a main method which is supposed to run periodically for an average period of 4 weeks.
This file uses its own session (pure sqlalchemy session) and connects to this app (which uses flask-sqlalchemy session).
After a few hours (sometimes 1 day), I get this error
Traceback (most recent call last):
File "/home/ubuntu/cron/runnable.py", line 781, in <module>
main()
File "/home/ubuntu/cron/runnable.py", line 677, in main
db_process_attendee(attendee, eid, event_id)
File "/home/ubuntu/cron/runnable.py", line 78, in db_process_attendee
update_attendee_information(attendee, attributes, eid, event_id)
File "/home/ubuntu/cron/runnable.py", line 117, in update_attendee_information
update_attendee_profile(attendee, id_attendee_login, eid, event_id)
File "/home/ubuntu/cron/runnable.py", line 291, in update_attendee_profile
generate_company_tags_lower.generate_company_tags(id_attendee_login)
File "/home/ubuntu/cron/app/util/generate_company_tags_lower.py", line 28, in generate_company_tags
filter(a_p.id_attendee_login == id_attendee_login).\
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2426, in scalar
ret = self.one()
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2395, in one
ret = list(self)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2438, in __iter__
return self._execute_and_instances(context)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/query.py", line 2453, in _execute_and_instances
result = conn.execute(querycontext.statement, self._params)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 729, in execute
return meth(self, multiparams, params)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/elements.py", line 322, in _execute_on_connection
return connection._execute_clauseelement(self, multiparams, params)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 826, in _execute_clauseelement
compiled_sql, distilled_params
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 958, in _execute_context
context)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1159, in _handle_dbapi_exception
exc_info
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/compat.py", line 199, in raise_from_cause
reraise(type(exception), exception, tb=exc_tb)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 951, in _execute_context
context)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 436, in do_execute
cursor.execute(statement, parameters)
File "/usr/local/lib/python2.7/dist-packages/pymysql/cursors.py", line 134, in execute
result = self._query(query)
File "/usr/local/lib/python2.7/dist-packages/pymysql/cursors.py", line 282, in _query
conn.query(q)
File "/usr/local/lib/python2.7/dist-packages/pymysql/connections.py", line 767, in query
self._execute_command(COMMAND.COM_QUERY, sql)
File "/usr/local/lib/python2.7/dist-packages/pymysql/connections.py", line 957, in _execute_command
self._write_bytes(prelude + sql[:chunk_size-1])
File "/usr/local/lib/python2.7/dist-packages/pymysql/connections.py", line 916, in _write_bytes
raise err.OperationalError(2006, "MySQL server has gone away (%r)" % (e,))
sqlalchemy.exc.OperationalError: (OperationalError) (2006, "MySQL server has gone away (error(110, 'Connection timed out'))") 'SELECT a_p.id_attendee_profile AS a_p_id_attendee_profile, a_p.id_attendee_login AS a_p_id_attendee_login \nFROM a_p \nWHERE a_p.id_attendee_login = %s' (128368,)
I tried the following suggestions but they did not work:
• In my app config, adding "pymysql" to the SQLALCHEMY_DATABASE_URI
• Doing a db.session.commit() when I enter generate_company_tags(id_attendee_login) before writing a sql select query. I thought it would flush the session.
Btw, the sqlalchemy pool recycle value is set to less than the max in AWS RDS.
Any suggestions on how I can go solving this?

Flask-SQLAlchemy create_all()

When i run the dbManager.create_all() command, it runs with out errors but fails to create the tables. When i delete the database and run the create_all() command, i get the no such database as ##### error which i should get but when the database does exist, nothing happens.
Please can anyone see what i'm doing wrong?
from blogconfig import dbManager
class Art(dbManager.Model):
id = dbManager.Column(dbManager.Integer, primary_key = True)
title = dbManager.Column(dbManager.String(64), index = True, unique = True)
content = dbManager.Column(dbManager.Text(5000))
def __repr__(self):
return '<Art %r>' %(self.title)
EDIT
This is the shell command
from blogconfig import dbManager
>>> dbManager.create_all()
import models
>>> a = models.Art(title='des', content='asdfvhbdjbjdn')
>>> dbManager.session.add(a)
>>> dbManager.session.commit()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/scoping.py", line 149, in do
return getattr(self.registry(), name)(*args, **kwargs)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 721, in commit
self.transaction.commit()
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 354, in commit
self._prepare_impl()
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 334, in _prepare_impl
self.session.flush()
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 1818, in flush
self._flush(objects)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 1936, in _flush
transaction.rollback(_capture_exception=True)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/langhelpers.py", line 58, in __exit__
compat.reraise(exc_type, exc_value, exc_tb)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/session.py", line 1900, in _flush
flush_context.execute()
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/unitofwork.py", line 372, in execute
rec.execute(self)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/unitofwork.py", line 525, in execute
uow
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/persistence.py", line 64, in save_obj
table, insert)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/orm/persistence.py", line 569, in _emit_insert_statements
execute(statement, params)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 662, in execute
params)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 761, in _execute_clauseelement
compiled_sql, distilled_params
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 874, in _execute_context
context)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1024, in _handle_dbapi_exception
exc_info
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/compat.py", line 195, in raise_from_cause
reraise(type(exception), exception, tb=exc_tb)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 867, in _execute_context
context)
File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 324, in do_execute
cursor.execute(statement, parameters)
File "/usr/lib/python2.7/dist-packages/MySQLdb/cursors.py", line 174, in execute
self.errorhandler(self, exc, value)
File "/usr/lib/python2.7/dist-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
raise errorclass, errorvalue
sqlalchemy.exc.ProgrammingError: (ProgrammingError) (1146, "Table 'blog.art' doesn't exist") 'INSERT INTO art (title, content) VALUES (%s, %s)' ('des', 'asdfvhbdjbjdn')
dbManager will not know about the models you define in other modules unless they are imported before running create_all.
In a real application this shouldn't matter because running the flask app should set up the db and import views/blueprints to register them. Since the views use the models, the models are indirectly imported and are available to the dbManager.
Either import your models in the blogconfig module after creating the dbManager instance, or change the order of you shell commands to be
>>> from blogconfig import dbManager
>>> import models
>>> dbManager.create_all()
SQLAlchemy will only create tables, the database must already exist, which is why you're seeing the other error when you delete the database.

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