A transaction problem encountered by Python using MySQLdb

When I use mysqldb today, when I find that a record is updated, select does not update and then discovers that it is a transaction problem.

When I operate MySQL in Python, I always use mysqldb, and this MYSQLDB library is the default shutdown autocommit transaction, that is, if you do not set the set autocommit=1 explicitly in the program, the table with the transaction function, For example, when the engine's InnoDB table is modified, a commit is executed each time to actually commit the current modification.

Here are my previous settings and the autocommit values I queried

Importmysqldbdb=MySQLdb.connect (myhost,myuser,mypass,mydb) Db.set_character_set ('UTF8') Cursor= Db.cursor (Cursorclass =MySQLdb.cursors.DictCursor) Cursor.execute ('SET NAMES UTF8;') SQL='Show variables like "autocommit"'cursor.execute (SQL) record=Cursor.fetchone ()PrintRecord#execution results are{'Value':'OFF','variable_name':'autocommit'}

This didn't happen before. Today, however, when I write a circular query function for a queue, I find that if I query a record first, then modify the record and then query this record, I cannot find the modified record.

The problem was in my use of the business. Although I used a commit for a statement with a modification operation (update,delete), I did not commit the select, which would cause my select to always be in a transaction, I can't query the record in this transaction, unless I explicitly commit the current transaction before I make the next query, so that I can get the latest data when I query again.

Fix it: Once the database is created, I explicitly specify Autocommit as 1, then the select problem is resolved

 #  -*-coding:utf-8-*- import   mysqldbdb  = MySQLdb.connect (Myhost,myuser,mypass,mydb) db.set_character_set (  " Span style= "COLOR: #800000" >utf8   " ) cursor  = Db.cursor (cursorclass = MySQLdb.cursors.DictCursor) Cursor.execute ( Span style= "COLOR: #800000" > " set NAMES UTF8;   " ) cursor.execute (  "  SET autocommit=1;    ") #   explicitly specifies that you want to automatically commit a transaction  

PS. Why has not been a problem before, because the previous execution of this script with a scheduled task, each time the program executes the exit, MySQL connection automatically shut down, and now I am writing a queue processing script has been executed, MySQL connection is continuous, the problem is exposed.

A transaction problem encountered by Python using MySQLdb