I'd like to access mydb variable on line 15, but it can¨t be seen. Even though I would go for Global variable, it still stays the same.
Code:
import mysql.connector
def connect():
try:
mydb = mysql.connector.connect(
host='localhost',
user='root',
password='12345',
database="Food"
)
except:
print("Possibly wrong PWD")
mycursor = mydb.cursor()
Error:
NameError: name 'mydb' is not defined
Thanks a lot.
did you call a function? I see you defined it, but don't see where you call it. Try
import mysql.connector
def connect():
try:
return mysql.connector.connect(
host='localhost',
user='root',
password='12345',
database="Food"
)
except:
print("Possibly wrong PWD")
mydb = connect()
mycursor = mydb.cursor()
I'm using MySqldb with Python 2.7 to allow Python to make connections to another MySQL server
import MySQLdb
db = MySQLdb.connect(host="sql.domain.com",
user="dev",
passwd="*******",
db="appdb")
Instead of connecting normally like this, how can the connection be made through a SSH tunnel using SSH key pairs?
The SSH tunnel should ideally be opened by Python. The SSH tunnel host and the MySQL server are the same machine.
Only this worked for me
import pymysql
import paramiko
import pandas as pd
from paramiko import SSHClient
from sshtunnel import SSHTunnelForwarder
from os.path import expanduser
home = expanduser('~')
mypkey = paramiko.RSAKey.from_private_key_file(home + pkeyfilepath)
# if you want to use ssh password use - ssh_password='your ssh password', bellow
sql_hostname = 'sql_hostname'
sql_username = 'sql_username'
sql_password = 'sql_password'
sql_main_database = 'db_name'
sql_port = 3306
ssh_host = 'ssh_hostname'
ssh_user = 'ssh_username'
ssh_port = 22
sql_ip = '1.1.1.1.1'
with SSHTunnelForwarder(
(ssh_host, ssh_port),
ssh_username=ssh_user,
ssh_pkey=mypkey,
remote_bind_address=(sql_hostname, sql_port)) as tunnel:
conn = pymysql.connect(host='127.0.0.1', user=sql_username,
passwd=sql_password, db=sql_main_database,
port=tunnel.local_bind_port)
query = '''SELECT VERSION();'''
data = pd.read_sql_query(query, conn)
conn.close()
I'm guessing you'll need port forwarding. I recommend sshtunnel.SSHTunnelForwarder
import mysql.connector
import sshtunnel
with sshtunnel.SSHTunnelForwarder(
(_host, _ssh_port),
ssh_username=_username,
ssh_password=_password,
remote_bind_address=(_remote_bind_address, _remote_mysql_port),
local_bind_address=(_local_bind_address, _local_mysql_port)
) as tunnel:
connection = mysql.connector.connect(
user=_db_user,
password=_db_password,
host=_local_bind_address,
database=_db_name,
port=_local_mysql_port)
...
from sshtunnel import SSHTunnelForwarder
import pymysql
import pandas as pd
tunnel = SSHTunnelForwarder(('SSH_HOST', 22), ssh_password=SSH_PASS, ssh_username=SSH_UNAME,
remote_bind_address=(DB_HOST, 3306))
tunnel.start()
conn = pymysql.connect(host='127.0.0.1', user=DB_UNAME, passwd=DB_PASS, port=tunnel.local_bind_port)
data = pd.read_sql_query("SHOW DATABASES;", conn)
credits to https://www.reddit.com/r/learnpython/comments/53wph1/connecting_to_a_mysql_database_in_a_python_script/
If your private key file is encrypted, this is what worked for me:
mypkey = paramiko.RSAKey.from_private_key_file(<<file location>>, password='password')
sql_hostname = 'sql_hostname'
sql_username = 'sql_username'
sql_password = 'sql_password'
sql_main_database = 'sql_main_database'
sql_port = 3306
ssh_host = 'ssh_host'
ssh_user = 'ssh_user'
ssh_port = 22
with SSHTunnelForwarder(
(ssh_host, ssh_port),
ssh_username=ssh_user,
ssh_pkey=mypkey,
ssh_password='ssh_password',
remote_bind_address=(sql_hostname, sql_port)) as tunnel:
conn = pymysql.connect(host='localhost', user=sql_username,
passwd=sql_password, db=sql_main_database,
port=tunnel.local_bind_port)
query = '''SELECT VERSION();'''
data = pd.read_sql_query(query, conn)
print(data)
conn.close()
You may only write the path to the private key file: ssh_pkey='/home/userName/.ssh/id_ed25519' (documentation is here: https://sshtunnel.readthedocs.io/en/latest/).
If you use mysql.connector from Oracle you must use a construction
cnx = mysql.connector.MySQLConnection(...
Important: a construction
cnx = mysql.connector.connect(...
does not work via an SSh! It is a bug.
(The documentation is here: https://dev.mysql.com/doc/connector-python/en/connector-python-connectargs.html).
Also, your SQL statement must be ideal. In case of an error on SQL server side, you do not receive an error message from SQL-server.
import sshtunnel
import numpy as np
with sshtunnel.SSHTunnelForwarder(ssh_address_or_host='ssh_host',
ssh_username="ssh_username",
ssh_pkey='/home/userName/.ssh/id_ed25519',
remote_bind_address=('localhost', 3306),
) as tunnel:
cnx = mysql.connector.MySQLConnection(user='sql_username',
password='sql_password',
host='127.0.0.1',
database='db_name',
port=tunnel.local_bind_port)
cursor = cnx.cursor()
cursor.execute('SELECT * FROM db_name.tableName;')
arr = np.array(cursor.fetchall())
cursor.close()
cnx.close()
This works for me:
import mysql.connector
import sshtunnel
with sshtunnel.SSHTunnelForwarder(
('ip-of-ssh-server', 'port-in-number-format'),
ssh_username = 'ssh-username',
ssh_password = 'ssh-password',
remote_bind_address = ('127.0.0.1', 3306)
) as tunnel:
connection = mysql.connector.connect(
user = 'database-username',
password = 'database-password',
host = '127.0.0.1',
port = tunnel.local_bind_port,
database = 'databasename',
)
mycursor = connection.cursor()
query = "SELECT * FROM datos"
mycursor.execute(query)
Someone said this in another comment. If you use the python mysql.connector from Oracle then you must use a construction cnx = mysql.connector.MySQLConnection(....
Important: a construction cnx = mysql.connector.connect(... does not work via an SSH! This bug cost me a whole day trying to understand why connections were being dropped by the remote server:
with sshtunnel.SSHTunnelForwarder(
(ssh_host,ssh_port),
ssh_username=ssh_username,
ssh_pkey=ssh_pkey,
remote_bind_address=(sql_host, sql_port)) as tunnel:
connection = mysql.connector.MySQLConnection(
host='127.0.0.1',
port=tunnel.local_bind_port,
user=sql_username,
password=sql_password)
query = 'select version();'
data = pd.read_sql_query(query, connection)
print(data)
connection.close()
If you are using python, and all the username, password, host and port are correct then there is just one thing left, that is using the argument (use_pure=True). This argument uses python to parse the details and password. You can see the doc of mysql.connector.connect() arguments.
with sshtunnel.SSHTunnelForwarder(
(ssh_host,ssh_port),
ssh_username=ssh_username,
ssh_pkey=ssh_pkey,
remote_bind_address=(sql_host, sql_port)) as tunnel:
connection = mysql.connector.MySQLConnection(
host='127.0.0.1',
port=tunnel.local_bind_port,
user=sql_username,
password=sql_password,
use_pure='True')
query = 'select version();'
data = pd.read_sql_query(query, connection)
print(data)
connection. Close()
Paramiko is the best python module to do ssh tunneling. Check out the code here:
https://github.com/paramiko/paramiko/blob/master/demos/forward.py
As said in comments this one works perfect.
SSH Tunnel for Python MySQLdb connection
Best practice is to parameterize the connection variables.
Here is how I have implemented. Works like charm!
import mysql.connector
import sshtunnel
import pandas as pd
import configparser
config = configparser.ConfigParser()
config.read('c:/work/tmf/data_model/tools/config.ini')
ssh_host = config['db_qa01']['SSH_HOST']
ssh_port = int(config['db_qa01']['SSH_PORT'])
ssh_username = config['db_qa01']['SSH_USER']
ssh_pkey = config['db_qa01']['SSH_PKEY']
sql_host = config['db_qa01']['HOST']
sql_port = int(config['db_qa01']['PORT'])
sql_username = config['db_qa01']['USER']
sql_password = config['db_qa01']['PASSWORD']
with sshtunnel.SSHTunnelForwarder(
(ssh_host,ssh_port),
ssh_username=ssh_username,
ssh_pkey=ssh_pkey,
remote_bind_address=(sql_host, sql_port)) as tunnel:
connection = mysql.connector.connect(
host='127.0.0.1',
port=tunnel.local_bind_port,
user=sql_username,
password=sql_password)
query = 'select version();'
data = pd.read_sql_query(query, connection)
print(data)
connection.close()
I've been given a postgres DB in my uni project in which I have to SSH into the network from which I can then access the DB. I've set up the connection in DBeaver using the SSH tab and it works perfectly fine. However, using Python, I can connect to the SSH just fine, but cannot connect to the DB itself. I've checked with another DB that doesn't require SSH and that works just fine. Here is my code. Note: I've already tried using SSHTunnel, too, to no avail. Also, ignore my quick hack to anonymize my SSH login data, as I didn't find how to use a proper config file with paramiko late at night yesterday...
import os
from psycopg2 import connect, Error
from paramiko import SSHClient
from config import config
with open("ssh_config.txt", "r") as f:
lines = f.readlines()
hostname = lines[0].strip()
username = lines[1].strip()
password = lines[2].strip()
ssh = SSHClient()
ssh.load_host_keys(os.path.expanduser('~/.ssh/known_hosts'))
ssh.connect(hostname=hostname, username=username, password=password)
print("SSH connected.")
try:
params = config()
conn = connect(**params)
cursor = conn.cursor()
print("DB connected.")
# Print PostgreSQL connection properties.
print(conn.get_dsn_parameters(), "\n")
# Print PostgreSQL version.
cursor.execute("SELECT version();")
record = cursor.fetchone()
print("You are connected to - ", record, "\n")
except (Exception, Error) as error:
print("Error while connecting to PostgreSQL", error)
Any help would be appreciated. Thanks!
I've figured it out myself. Here is the updated code. Basically, I had to forward the remote address to localhost and then connect to localhost instead of the DB address.
from psycopg2 import connect, Error
from sshtunnel import SSHTunnelForwarder
from config import config
with open("ssh_config.txt", "r") as f:
lines = f.readlines()
hostname = lines[0].strip()
username = lines[1].strip()
password = lines[2].strip()
remote_bind_address = lines[3].strip()
try:
with SSHTunnelForwarder(
(hostname, 22),
ssh_username=username,
ssh_password=password,
remote_bind_address=(remote_bind_address, 5432),
local_bind_address=("localhost", 8080)) \
as tunnel:
tunnel.start()
print("SSH connected.")
params = config()
conn = connect(**params)
cursor = conn.cursor()
print("DB connected.")
# Print PostgreSQL connection properties.
print(conn.get_dsn_parameters(), "\n")
# Print PostgreSQL version.
cursor.execute("SELECT version();")
record = cursor.fetchone()
print("You are connected to - ", record, "\n")
cursor.close()
conn.close()
tunnel.close()
print("DB disconnected.")
except (Exception, Error) as error:
print("Error while connecting to DB", error)
I have database in MySQL workbench and I'm running Python code from shell to connect to my database.
But I am unable to import mysql.connector or mysqlDb (got this suggestion from w3school). So I am unable to connect to my database.
I think the question does not concern connecting with Putty, but more about importing mysql.connector in your python script.
"But I am unable to import mysql.connector or mysqlDb ( got this suggestion form w3school)"
--It will be easier to help you if your code is attached to your post.
import mysql.connector
cnx = mysql.connector.connect(########)
think this scrap of code will be helpful."Loading file from Oracle"
def load_file(DT):
ip = ######
port = #####
service_name = '#####'
dsn = cx_Oracle.makedsn(ip, port, service_name=service_name)
t = datetime.now().strftime("%Y%m%d%H%M%S")
SQL = "select name...."
fn = "/root/..." + t + ".csv"
fn_tmp = "/root/.." + t + ".csv"
FILE = open(fn_tmp, "w")
FILE.write(
'name...;' + '\n')
out = csv.writer(FILE, delimiter=';')
logging.info("Database connect " + t)
try:
conn = cx_Oracle.connect('####', '###', dsn)
cur = conn.cursor()
cur.execute(SQL)
except cx_Oracle.DatabaseError, exc:
conn = None
error, = exc.args
logging.error(
"Oracle connection problem Error Code:{0}".format(str(error).decode("####",
"ignore").encode("utf-8",
"ignore"))
)
for row in cur:
out.writerow(localize_floats(row))
logging.info("Database disconnect " + t)
try:
cur.close()
conn.close()
except cx_Oracle.DatabaseError, exc:
error, = exc.argsgv[0]
logging.error("Oracle-Error-Code:{0}".format(str(error).decode("####",
"ignore").encode("utf-8",
"ignore"))
)
FILE.close()
os.rename(fn_tmp, fn)
An option that you can try is to use pymysql. More info here. A code snippet is the following:
import pymysql.cursors
connection = pymysql.connect(host='IP',
port=3306,
user='user',
password='pass',
db='database',
charset='utf8mb4',
autocommit=True,
cursorclass=pymysql.cursors.DictCursor)
with connection.cursor() as cursor:
query = 'Your query'
cursor.execute(query)
connection.close()
I am trying to make a login system with python and mysql. I connected to the database, but when I try to insert values into a table, it fails. I'm not sure what's wrong. I am using python 3.5 and the PyMySQL module.
#!python3
import pymysql, sys, time
try:
print('Connecting.....')
time.sleep(1.66)
conn = pymysql.connect(user='root', passwd='root', host='127.0.0.1', port=3306, database='MySQL')
print('Connection suceeded!')
except:
print('Connection failed.')
sys.exit('Error.')
cursor = conn.cursor()
sql = "INSERT INTO login(USER, PASS) VALUES('test', 'val')"
try:
cursor.execute(sql)
conn.commit()
except:
conn.rollback()
print('Operation failed.')
conn.close()
I think it may have to do with the order of the statements in the connection. According to the PyMySQL github (found here) the correct order is host, port, user, passwd, db.
Like this :
user = input("User: ")
pass = input("Pass: ")
sql = "INSERT INTO login(USER, PASS) VALUES('%s', '%s')"%(user, pass)
btw you should connect like this :
conn = pymysql.connect(
host='127.0.0.1',
user='root',
passwd='root',
db='MySQL
)