Problem accessing MySQL connection out of Flask methods - python-3.x

Question

I'm developing a Flask app, with MySQL (flask-mysqldb) and MQTT (flask-mqtt) integrations. I can perform any DB operation from a Flask method (e.g. #app.route('/')), but if I try to do it from a MQTT method when I receive a message (e.g. #mqtt.on_message()) it does nothing. This last method works perfectly because it receives and shows in log the message received.
I have a method that performs DB operations, and depending on where I call it from, it works or not. I guess it should be because of the MySQL object, but I don't know exactly.
Here is the code I'm using (just the problem):
#mqtt.on_message()
def handle_mqtt_message(client, userdata, message):
print('New message {}'.format(message.payload.decode()))
storeDB('test') #Here it doesn't work
################## Methods ###########################
def storeDB(param_text):
cur = mysql.connection.cursor()
cur.execute(
'INSERT INTO contacts (fullname, phone, email) VALUES (%s,%s,%s)', (param_text, param_text, param_text))
mysql.connection.commit()
###################### FLASK #########################
#app.route('/')
def index():
storeDB('temp') #Here it works
return 'Hello World'
If I access to localhost it shows the "Hello World" text in browser and updates the DB; otherwise, if I receive a MQTT message, it is shown on terminal but not updated the DB.
Thanks.

Answer 1

This is how I have it working using the MySQLdbpackage:
import MySQLdb
try:
db = MySQLdb.connect("HOST", "USER", "PASS", "DB")
except:
print("Problem creating DB connection")
sys.exit()
cursor = db.cursor()
def storeDB(param_text1, param_text2, param_text3):
query = """INSERT INTO `DB`.`TABLE` (`fullname`, `phone`, `email`) VALUES ('""" + \
param_text1+"""','"""+param_text2+"""','"""+param_text3+"""');"""
try:
cursor.execute(query)
db.commit()
print('DB updated')
except:
db.rollback()
print("Problem updating DB :(")