Am receiving json data (from an other python script) to put inside MYSQL database, the code work fine the first time but the second time I got this error:
raise errors.OperationalError("MySQL Connection not available.")
mysql.connector.errors.OperationalError: MySQL Connection not available.
For troubleshooting am sending always the same data, but it still write an error the second time.
I tried also from information found on furums to place : cur = mydb.cursor() at diferents places but I have never been able to get this code work the second time.
There is my code :
import mysql.connector
import json
mydb = mysql.connector.connect(
host="localhost",
user="***",
passwd="***",
database="***"
)
def DATA_REPARTITION(Topic, jsonData):
if Topic == "test":
#print ("Start")
INSERT_DEBIT(jsonData)
def INSERT_DEBIT(jsonData):
cur = mydb.cursor()
#Read json from MQTT
print("Start read data to insert")
json_Dict = json.loads(jsonData)
debit = json_Dict['debit']
print("I send")
print(debit)
#Insert into DB Table
sql = ("INSERT INTO debit (data_debit) VALUES (%s)")
val=debit,
cur.execute(sql,val)
mydb.commit()
print(cur.rowcount, "record inserted.")
cur.close()
mydb.close()
Thanks for your help!
You only open your database connection once, at the start of the script, and you close that connection after making the first insert. Hence, second and subsequent inserts are failing. You should create a helper function which returns a database connection, and then call it each time you want to do DML:
def getConnection():
mydb = mysql.connector.connect(
host="localhost",
user="***",
passwd="***",
database="***")
return mydb
def INSERT_DEBIT(jsonData):
mydb = getConnection()
cur = mydb.cursor()
# Read json from MQTT
# rest of your code here...
cur.close()
mydb.close()
Related
This question already has answers here:
psycopg2 not actually inserting data
(2 answers)
Closed 2 months ago.
I am running this python code to read in quotes from a file and then insert each quote into a table in my database. When I run the script in my terminal there are no errors but when I go to the database table I tried to insert to it tells me there are 0 rows.
#!/usr/bin/python
import psycopg2
import re
from config import config
conn = psycopg2.connect(
host="localhost",
database="favorite_quotes",
user="postgres",
password="???")
data = None
with open('file.txt', 'r') as file:
data = file.read()
list_of_strings = re.findall('“(.+?)” \(.+?\)', data, re.DOTALL)
def insert_quotes():
""" Connect to the PostgreSQL database server """
conn = None
try:
# read connection parameters
params = config()
# connect to the PostgreSQL server
print('Connecting to the PostgreSQL database...')
conn = psycopg2.connect(**params)
# create a cursor
cur = conn.cursor()
for str in list_of_strings:
cur.execute("INSERT INTO the_courage_to_be_disliked (quote) VALUES (%s)", [str])
# execute a statement
# dblist = list(cur.fetchone())
# quotes = []
# for row in cur:
# quotes.append(row[1])
# return quotes
# close the communication with the PostgreSQL
cur.close()
except (Exception, psycopg2.DatabaseError) as error:
print(error)
finally:
if conn is not None:
conn.close()
print('Database connection closed.')
if __name__ == '__main__':
insert_quotes()
You aren't committing your inserts, so they won't be visible from outside the current connection, and will be implicitly rolled back when the connection is closed.
TL;DR, add a call to conn.comimt() before calling conn.close().
So i want to store my XML data to database using python connector to mysql.
import mysql.connector
from getpass import getpass
from mysql.connector import connect, Error
import xml.etree.ElementTree as ET
mydb = mysql.connector.connect(
host="localhost",
user="root",
password="",
database="results"
)
if mydb:
print ("Connected Successfully")
else:
print ("Connection Not Established")
tree = ET.parse('report.xml')
res = tree.findall('entry')
for test in res:
name = test.find('name').text
verdict = test.find.int('verdict').text
description = test.find('description').text
report = """INSERT INTO test_executions (name,verdict,description)
VALUES(%s,%s,%s)"""
cursor = mydb.cursor()
cursor.execute(report,(name,verdict,description))
mydb.commit()
print("Data inserted successfully.")
print(mycursor.rowcount, "record inserted.")
I already have this code but everytime i run it, it never go through the for loop and commit the insertion to my DB. Is there something wrong with the code?
I have a program like this:
def runBlockHash(i):
#Somethings here#
sql='SELECT * from abc where zzz=xyz'
mycursor.execute(sql, hashTree)
results = mycursor.fetchall()
#Something more here##
print("Connecting to SQL DB")
mydb = mysql.connector.connect(
host=args['hostname'],
user=args['username'],
passwd=args['password'],
database=args['database']
)
mycursor = mydb.cursor()
p=mp.Pool(2) #Define Number of Process to Use
p.map(runBlockHash,range(len(files_to_process))) # Call the function
p.close() #Close the multi threads
p.join()
But the problem I am facing is, when i have more than 1 CPU, not even a single sql query is executed. Python program just freeze.
I just want to run select statements. I don't want to insert or update the database.
i have to connect to mysql server and grab some data for ever
so i have two way
1)connect to mysql the grab data in a while
conn = mysql.connector.connect(user='root',password='password',host='localhost',database='db',charset='utf8',autocommit=True)
cursor = conn.cursor(buffered=True)
while True:
cursor.execute("statments")
sqlData = cursor.fetchone()
print(sqlData)
sleep(0.5)
this working good but if script crashed due to mysql connection problem script goes down
2)connect to mysql in while
while True:
try:
conn = mysql.connector.connect(user='root',password='password',host='localhost',database='db',charset='utf8',autocommit=True)
cursor = conn.cursor(buffered=True)
cursor.execute("statments")
sqlData = cursor.fetchone()
print(sqlData)
cursor.close()
conn.close()
sleep(0.5)
except:
print("recoverable error..")
both code working good but my question is which is better?!
Among these two, better way will be to use a single connection but create a new cursor for each statement because creation of new connection takes time but creating a new cursor is fast. You may update the code as:
conn = mysql.connector.connect(user='root',password='password',host='localhost',database='db',charset='utf8',autocommit=True)
while True:
try:
cursor = conn.cursor(buffered=True)
cursor.execute("statments")
sqlData = cursor.fetchone()
print(sqlData)
except Exception: # Catch exception which will be raise in connection loss
conn = mysql.connector.connect(user='root',password='password',host='localhost',database='db',charset='utf8',autocommit=True)
cursor = conn.cursor(buffered=True)
finally:
cursor.close()
conn.close() # Close the connection
Also read Defining Clean-up Actions regarding the usage of try:finally block.
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
)