Python Module Mysql-connector Does Not See New Changes

问题

I use mysql.connector to fetch rows in a python script but when I update a table the I don't see the changes.

My code is:

import mysql.connector

database = mysql.connector.connect(host='localhost', user='root', passwd='password', database='my_db')
cursor = database.cursor()

cursor.execute('SELECT * FROM my_table')
print(cursor.fetchall())

cursor.execute('SELECT * FROM my_table')
print(cursor.fetchall())

In first time it reads the correct values but at the second time it reads the same values as in the first time even though I have updated my_table mysql.connector does not see any changes.

Do anyone have any ideas on how to solve this problem? Thanks!

回答1:

When use performs DML like update, delete, etc You have to commit cursor after performing the operation otherwise your operation not save. There are use case of commit cursor some time

• due to the electricity issue
• atomicity transaction will rollback or commit latter

like

import mysql.connector

database = mysql.connector.connect(host='localhost', user='root', passwd='password', database='my_db')
cursor = database.cursor()

try:  
    cursor.execute("update Employee set name = 'alex' where id = 110")  
    cursor.commit()  
except:  
    cursor.rollback()  
  
cursor.close()  

commit if the update will succeed otherwise rollback if got any error at the database level

or you can pass autocommit=True when you connect with database it will work too it's global configuration it will commit of some interval of time like

database = mysql.connector.connect(host='localhost', user='root', passwd='password', database='my_db', autocommit=True)
cursor = database.cursor()

来源：https://stackoverflow.com/questions/65882125/python-module-mysql-connector-does-not-see-new-changes