mysql transaction

$ Linkid = mysql_connect ('localhost: 100', 'root ',*******); Mysql_select_db ('web _ his ', $ linkid ); Mysql_query ("set names utf8 "); /* Create a transaction */ Mysql_query ('start transaction') or exit (mysql_error ()); $ Ssql1 = "insert

Today and students to discuss the issue of database transactions, feel the discussion in some understanding, some knowledge has been seen, but no actual use or do not understand. A transaction is a sequence of operations as an atomic operation, or

Transaction processing in various management systems have a wide range of applications, such as personnel management system, many synchronous database operations need to use transactions. For example, in a personnel management system, you delete a

Therefore, the correct atomic operation is actually performed. is physical execution. You can actually see the inserted record in the current transaction. At last it was only deleted. However, Auto_increment should not delete and change the value.

In E-commerce, there will often be a small number of inventory, the purchase of the person is particularly large, concurrency in the case of how to ensure that the number of goods will not be purchased multiple times. In fact very simple, use the

This article illustrates the example of PHP using MySQL, and provides a detailed explanation with annotations. Share for everyone to use for reference. The specific examples are as follows: It is hoped that the examples mentioned in

MySQL database power-on error： Innodb:the log sequence number in Ibdata files does not match Innodb:the log sequence number in the ib_logfiles! 100224 12:24:20 Innodb:database is not shut down normally! Innodb:starting crash recovery. innodb:reading

MySQL transaction and isolation levelsConnection Manager:Accept RequestCreating ThreadsCertified UsersEstablish a secure connectionConcurrency control:The simplest mechanism is to use locksMulti-version concurrency control: MVCC (using other

Reprinted from:MySQL Transaction ISOLATION level detailedThe SQL standard defines a Class 4 isolation level, which includes specific rules to define which changes within and outside the transaction are visible and which are not. Low-level isolation

ConceptThe isolation level is used to determine how concurrent users can read and write data, while also having a certain impact on performance.Dirty read: READ UNCOMMITTED data;Non-repeatable read (Non-repeatable Read): The data is inconsistent in

One or four levels of isolationREAD UNCOMMITTED (Read UNCOMMITTED content)At this isolation level, all transactions can see the execution results of other uncommitted transactions. This isolation level is rarely used in real-world applications

In a database, a transaction is a series of operations performed as a single logical unit of work. Transaction operations: First define the start of a transaction, and then modify the data, if committed, these changes are permanently saved if the

1, experimental environmentMYQL version 5.7.17-logExperimental table structure([email protected]) [apex]> show create table test;+-------+----------------------------------------------- ----------------------------------------------------------------

MySQL Transaction ISOLATION level detailed      MySQL data structure SQLThe SQL standard defines a Class 4 isolation level, which includes specific rules to define which changes within and outside the transaction are visible and which are not.

The version of MySQL I am applying is: 5.6.22MySQL5.5 later uses the InnoDB storage engine by default, where InnoDB and BDB provide transaction-safe tables, and other storage engines are non-transactional security tables. you can specify the engine

Background Mysql/innodb's locking analysis has been a difficult topic. In the course of my work, my colleagues have often consulted on this issue. At the same time, the micro-blog also often receive the MySQL lock-related private messages, let

MySQL's own Mysqlbinlog | MySQL rollback is not good for you to write a simple script to try:The idea is to use Mysqlbinlog to find the transaction area that needs to be rolled back from Mysql-bin.file and then insert the DB through the script.# #

A transaction is the execution unit of a DBMS. It is made up of a limited number of database operation sequences. But not any database operation sequence can be a transaction. In general, transactions are required to meet 4 conditions

PHP/*PDO Learning*/ $dsn= ' MYSQL:HOST=LOCALHOST;DBNAME=CSWL ';//Build a Connection DSN $db=NewPdo$dsn, ' root ', ');//instantiate PDO "the second parameter is the user name, the third is the password" #. Transactional features

Mysql_query ("BEGIN"); // starts a transaction.Mysql_query ("set autocommit = 0"); // you can specify that the transaction is not automatically committed.$ Insert = "insert into userinfo VALUES ('aa12', 'A', '1', 'aaa ')";Mysql_query ($ insert