mysql multiprocess - fetch data while writing

问题

I need to log data from sensor as fast as possible. Therefore I start a process for continuously writing data to MySQL database by a parallel running thread in python.

After I started this thread, I need to frequently fetch some data of the database, which have been inserted of the active thread.

The issue is, that I can´t get acces to the data while the thread is running. after I stop the thread, I can read the data out of the database. I also tried to "commit" the writing every on every row, but it still does not work.

Here is my test-script:

import mysql.connector
from mysql.connector import pooling
import datetime, json, threading


mydb = mysql.connector.pooling.MySQLConnectionPool( pool_size = 3,
                                                    host = "localhost",
                                                    user = "user",
                                                    passwd = "password",
                                                    database = "any"
                                                )

connection = mydb.get_connection()
connection_1 = mydb.get_connection()

my_cursor = connection.cursor()
my_cursor_1 = connection_1.cursor()

def continous_process():
    while True:
        cmd = "INSERT INTO config (config_json, date) VALUES (%s, %s)"
        date = datetime.datetime.now()
        values = (json.dumps("something"), date)
        my_cursor.execute(cmd, values)
        my_cursor.execute("COMMIT")

def get_last_config():
        my_cursor_1.execute("SELECT entry_id FROM config ORDER BY entry_id DESC LIMIT 1")
        print(my_cursor_1.fetchall()[0])

my_thread = threading.Thread(target=continous_process)
my_thread.start()
print(my_thread.is_alive())

while True:
    print(get_last_config())

Is it necessary to release the connection by connection.release() after each entry? Im looking forward to a performant solution, which is alsmost "realtime".

来源：https://stackoverflow.com/questions/62166481/mysql-multiprocess-fetch-data-while-writing