Im currently attempting to follow a youtube tutorial on how to connect a database through Pycharm however it's not connecting and I'm not sure where the problem is or how I am able to solve it. the code is:
import mysql.connector
from mysql.connector import errorcode
try:
cnn = mysql.connector.connect(
user='root',
password='root',
host='localhost',
database='name')
print("it works")
except mysql.connector.Error as e:
if e.errno == errorcode.ER_ACCESS_DENIED_ERROR:
print("something is wrong with username and password")
elif e.errno == errorcode.ER_BAD_DB_ERROR:
print("database does not exist")
else:
print("E")
cursor = cnn.cursor()
addName = "INSERT INTO name (fName, lName) values (%s, %s)"
fName = "Rae"
lName = "Smith"
empName = (fName, lName)
cursor.execute(addName, empName)
cnn.commit()
cursor.close()
cnn.close()
Once I run it I get the error:
Traceback (most recent call last):
something is wrong with username and password
line 19, in <module>
cursor = cnn.cursor()
NameError: name 'cnn' is not defined
I've seen the user on the tutorial receiving the same warning however when he runs his code there is no error like the one I receive. How I may be able to solve this?
Related
I am trying to create a database file using the following code:
def dbconnect():
try:
sqliteConnection = sqlite3.connect('SQLite_Python.db')
cursor = sqliteConnection.cursor()
print("Database created and Successfully Connected to SQLite")
sqlite_select_Query = "select sqlite_version();"
cursor.execute(sqlite_select_Query)
record = cursor.fetchall()
print("SQLite Database Version is: ", record)
cursor.close()
except sqlite3.Error as error:
print("Error while connecting to sqlite", error)
finally:
if sqliteConnection:
sqliteConnection.close()
print("The SQLite connection is closed")
conn = dbconnect()
conn.close()
yet when I run the code, although there are no file errors, it doesnt print anything or create a SQL file in the folder of the python code.
I can't seem to figure out what is going wrong.
I am trying to write several dataframes in mysql. I use mysql.connector for the connection and sqlalchemy to create an engine.
Most dataframes are written correctly to the database. Unfortunately the application stops with the following error:
sqlalchemy.exc.DatabaseError: (mysql.connector.errors.DatabaseError) 2006 (HY000): MySQL server has gone away
...
During handling of the above exception, another exception occurred:
...
_mysql_connector.MySQLInterfaceError: MySQL server has gone away
Since the dataframe that breaks the connection is also the largest one (pickle file: 198MB) I assumed that it is due to the MySql-Server setting max_allowed_packet or timeout. (As described here)
So I have extended the config file within my SQLConnector (see below) by 'connect_timeout': 900.
Unfortunately without result.
I have also read that you should adjust the my.cnf of the MySql server. Unfortunately I did not know exactly where to find them. After a long search I found the following order. C:\Program Files\MySQL\MySQL Server 8.0\etc with the file mysqlrouter.conf.sample.
Here I have downloaded a my.cnf file and put it into the folder. Unfortunately without result, because I did not know how to set up MySql so that the server uses this file.
Does anyone know how I can fix this error? Or how I can configure the MySql Server preference settings max_allowed_packet or timeout?
Main:
mysqlConnector = MySQLConnector()
dbConnection = mysqlConnector.init_engine()
for df_tuple in df_all_tuple:
df_name = df_tuple[0]
df = pd.DataFrame(df_tuple[1])
df.to_sql(con=mydb, name=df_name, if_exists='fail', chunksize=20000)
SQLConnector:
import mysql.connector
from mysql.connector import errorcode
import sqlalchemy as db
config = {
'user': 'root',
'password': '',
'host': '127.0.0.1',
'database': 'test',
'raise_on_warnings': True,
'use_pure': False,
'autocommit': True,
'connect_timeout': 900
}
class MySQLConnector:
def __init__(self):
connectTest = self.connect()
print("Connection to database: " + str(connectTest))
def init_engine(self):
try:
connect_string = 'mysql+mysqlconnector://{}:{}#{}/{}?charset=utf8mb4'.format(config.get("user"),
config.get("password"),
config.get("host"),
config.get("database"),
pool_pre_ping=True)
print("Engine: " + connect_string)
sqlengine = db.create_engine(connect_string)
except:
print("SQLConnector: Sqlalchemy error. Can't create engine....")
else:
dbConnection = sqlengine.connect()
return dbConnection
def connect(self):
try:
con = mysql.connector.connect(**config)
except mysql.connector.Error as err:
if err.errno == errorcode.ER_ACCESS_DENIED_ERROR:
print("Something is wrong with your user name or password")
elif err.errno == errorcode.ER_BAD_DB_ERROR:
print("Database does not exist")
if self.createDB() is True:
return self.connect()
elif err.errno == errorcode.CR_SERVER_GONE_ERROR:
print("The client couldn't send a question to the server.")
print("err: " + err)
elif err.errno == errorcode.CR_SERVER_LOST:
print(
"The client didn't get an error when writing to the server, but it didn't get a full answer (or any answer) to the question.")
print("err: " + err)
else:
print(err)
return None
else:
if con.is_connected():
db_Info = con.get_server_info()
print("Connected to MySQL Server version ", db_Info)
sqlcursor = con.cursor()
return con
def createDB(self):
try:
mydb = mysql.connector.connect(
host=config.get("host"),
user=config.get("user"),
passwd=config.get("password")
)
except mysql.connector.Error as err:
print(err)
else:
sqlcursor = mydb.cursor()
try:
sqlcursor.execute('CREATE DATABASE {}'.format(config.get("database")))
except mysql.connector.Error as err:
print(err)
return False
else:
print("Database created!")
return True
I am trying to test that an error is thrown in unittest with Python 3.6 when working with psycopg2. In this case, the database named foo does not existm, and it should throw an OperationalError because the database is not a valid one.
Here is a sample test case:
# -*- coding: utf-8 -*-
import unittest
import psycopg2
import logging
def pull_pg_data(conn, cursor, first, last):
try:
cursor.execute('SELECT first_name, last_name, email, street FROM user_data WHERE first_name =%s AND last_name=%s',(first, last))
except psycopg2.OperationalError as msg:
logging.error(msg)
raise
conn.commit()
result = cursor.fetchall()
return result
class SampleTestCases(unittest.TestCase):
def setUp(self):
try:
self.conn = psycopg2.connect(dbname='postgres', user='postgres', host='localhost', port=5432,
connect_timeout=10)
except psycopg2.OperationalError as msg:
logging.critical(msg)
raise
self.conn.autocommit = True
self.cursor = self.conn.cursor()
self.cursor.execute('DROP TABLE IF EXISTS user_data', [])
self.cursor.execute('CREATE TABLE user_data (first_name TEXT, last_name TEXT, email TEXT, street TEXT)', [])
self.cursor.execute("INSERT INTO user_data(first_name, last_name, email, street) VALUES('someFirstName', 'someLastName', 'some#example.com', '123 road')",[])
def test_pull_pg_data_fail(self):
conn = psycopg2.connect(dbname='foo', user='postgres', host='localhost', port=5432, connect_timeout=10)
cursor = conn.cursor()
self.assertRaises(psycopg2.OperationalError, pull_pg_data, conn, cursor, 'someFirstName', 'someLastName')
if __name__ == '__main__':
unittest.main()
When I run the test, it does indeed throw an error, but it fails the test. I don't know what I am doing incorrectly with assertRaises, because I do want to test that the error is thrown when I try to connect to a database that does not exist.
I am facing an error while executing a python script.
Checked with directly using the users and password.
Checked with saved the users and pass in variables too.
Script:
import mysql.connector,sys
try:
cnx = mysql.connector.connect (host='localhost', user = 'user', password = 'user#543', port= 3306)
except mysql.connector.errors.ProgrammingError, e:
print time.strftime("%Y-%m-%d %H:%M:%S"),"Error %s" % (e)
sys.exit(1)
except mysql.connector.errors.InterfaceError, e1:
print time.strftime("%Y-%m-%d %H:%M:%S"),"Error %s" % (e1)
sys.exit(1)
cursor = db.cursor()
cursor.execute("select version()")
result_set = cursor.fetchall()
print result_set
Error:
Traceback (most recent call last):
File "test.py", line 3, in <module>
cnx = mysql.connector.connect (host='localhost', user = 'user', password = 'user#543', port= 3306)
AttributeError: 'str' object has no attribute 'connector'
It's a typo. There's a space between connect and the argument list. Change the line to:
cnx = mysql.connector.connect(
host='localhost', user='user', password='user#543', port=3306
)
for a project at uni i need to insert different kinds of variables into a MySql Database. Connecting and Inserting the data so far works fine. I don't know how to handle potential errors though. Which potential mistakes and exceptions do i need to catch and take care of ?
In my code i used a main method to just test the program. In the final version just the connection and the SQL queries are copied into the main script. I am open to use either the MySQL or the mysql.connector. Also: Do i need to put the query into a try block aswell ? Here is my code so far:
import mysql.connector
import time
from mysql.connector import errorcode
try:
con = mysql.connector.connect(
user= 'root',
password= '',
host='localhost',
database= 'testdb')
print("Connected.")
cursor = con.cursor()
except mysql.connector.Error as e:
if e.errno == errorcode.ER_ACCESS_DENIED_ERROR:
print("Passwort // Username")
elif e.errno == errorcode.ER_BAD_DB_ERROR:
print("DataBase does not exist")
else:
print(e)
def insert_temp(Temperatur_ID, Zeitpunkt, Wert, Thermometer_ID):
query = "INSERT INTO Temperatur (Temperatur_ID, Zeitpunkt, Wert, Thermometer_ID)" \
"VALUES(%s, %s, %s, %s)"
args= (Temperatur_ID, Zeitpunkt, Wert, Thermometer_ID)
cursor.execute(query, args)
con.commit()
def main():
# just test values so far
value = 18.5;
insert_temp(' ', time.strftime('%Y-%m-%d %H:%M:%S'), value, '1');
cursor.close()
con.close()
if __name__ == '__main__':
main()
please note that i have very little experience in python programming