PHP operation MySQL Transaction instance, MySQL transaction instance _php tutorial

PHP operation MySQL Transaction instance, MySQL transaction instance

This article describes the PHP operation of the MySQL transaction methods, share to everyone for your reference. Here's how:

In general, transactions should have acid characteristics. The so-called acid is Atomic (atomicity), consistent (consistency), Isolated (isolation), durable (persistent) four words written in the first letter, the following "bank transfer" as an example to explain their meaning:

① atomicity: The statement that makes up the transaction forms a logical unit and cannot execute only part of it. In other words, a transaction is the smallest unit that is indivisible. For example, in a bank transfer process, you must subtract the transfer amount from one account and add it to another account, it is unreasonable to change only one account.
② Consistency: The database is consistent before and after the execution of the transaction. In other words, the transaction should correctly convert the System state. For example: During a bank transfer, the transfer amount is transferred from one account to another, or two accounts are not changed, and there is no other situation.
③ Isolation: One transaction has no effect on another transaction processing. This means that no transaction is likely to see a transaction in an incomplete state. For example, in a bank transfer process, another transfer transaction can only be in the waiting state until the transfer transaction is not committed.
④ Persistence: The effect of transaction processing can be permanently preserved. Conversely, transactions should be able to withstand all failures, including servers, processes, communications, media failures, and so on. For example: In the process of bank transfer, the status of transfer payback can be saved.

In PHP, MYSQLI has already encapsulated the operation of MySQL transactions well. The following example:
Copy CodeThe code is as follows: $sql 1 = "Update User set scorecount = Scorecount +10 where id= ' 123456 '";
$sql 2 = "Update scoredetail set fscore =" where id= ' 123456 ' ";
$sql 3 = "INSERT INTO Scoredetail id,score" values (' 123456 ', 60) ";
$mysqli = new mysqli (' localhost ', ' root ', ' ', ' db_lib2test ');
$mysqli->autocommit (FALSE);//Start things
$mysqli->query ($sql 1);
$mysqli->query ($sql 2);
if (! $mysqli->errno) {
$mysqli->commit ();
echo ' OK ';
}else{
echo ' err ';
$mysqli->rollback ();
}
Here, we then use the PHP MySQL series function to perform the transaction.
Copy CodeThe code is as follows: $sql 1 = "Update User set scorecount = Scorecount +10 where id= ' 123456 '";
$sql 2 = "Update scoredetail set fscore =" where id= ' 123456 ' ";
$sql 3 = "INSERT INTO Scoredetail id,score" values (' 123456 ', 60) ";
$conn = mysql_connect (' localhost ', ' root ', ');
mysql_select_db (' db_lib2test ');
mysql_query (' Start transaction ');
mysql_query (' SET autocommit=0 ');
mysql_query ($sql 1);
mysql_query ($sql 2);
if (Mysql_errno ()) {
mysql_query (' rollback ');
echo ' err ';
}else{
mysql_query (' commit ');
echo ' OK ';
}
mysql_query (' SET autocommit=1 ');
mysql_query ($sql 3);

Here to note:

MyISAM: Transactions are not supported for read-only programs to improve performance
InnoDB: Supports acid transactions, row-level locks, concurrency
Berkeley DB: Support transactions

It is hoped that this article is helpful to everyone's Php+mysql database program design.

Who gives a PHP operation MySQL class and has detailed usage instructions or examples

below this, is a simple database encapsulation class for PHP5, suitable for learning, and other actions such as delete, update, you can add yourself:
!--? php
class mysql{//First define a class, Uppercase letters
Public $host;//server name, access modifier publicly proves that $host is a common condition that is accessible inside and outside the class, can be inherited
public $user;//user name, is a common property
private $pass;//password, ask modifier private certificate $pass is private. Can only be used inside a class and cannot be inherited.
public $dbname;//database name, which is also a common property.
//__construct Reputation This is a constructor that defines some initial information. There are three parameters
Public function __construct ($host, $user, $pass, $dbname) {
$this- >host = $host;
$this->user = $user;
$this->pass = $pass;
$this->dbname = $dbname;
$link = @mysql_connect ($this->host, $this->user, $this->pass)
or Die ("error");
@mysql_select_db ( $this->dbname, $link)
or Die ("Error2");
}
//define lookup and display functions for the database
function myquery ($sql) {
$result = mysql_query ($sql);
if (! $result) {
echo "Error3";
Exit
}
$num = Mysql_num_rows ($result);
if ($num) {
echo "NO". $num;
}
while ($row = Mysql_fetch_assoc ($result)) {
echo '

'. Htmlspecialchars (Stripslashes ($row [' body ']). "
</td></tr> ";
}
}
}
$rutt = new Mysql (' localhost ', ' root ', ' ssss ', ' Calvin ');//Instantiate a class ... Remember that the parameters here are the same as the parameters of the constructor ...
$rutt->myquery (...) Remaining full text >>

Want to make a website, a PHP programming code, PHP MySQL cache how to implement? It's best to give an example
The following are the cache classes:

   Class Cache {
Cache Directory
var $cacheRoot = "./cache/";
Cache update time seconds, 0 for no cache
var $cacheLimitTime = 0;
Cache file Name
var $cacheFileName = "";
Cache extension
var $cacheFileExt = "html";

/*
* Constructor function
* int $cacheLimitTime Cache update Time
*/
function Cache ($cacheLimitTime) {
if (Intval ($cacheLimitTime))
$this->cachelimittime = $cacheLimitTime;
$this->cachefilename = $this->getcachefilename ();
Echo $this->cachefilename;
Ob_start ();
}

/*
* Check if the cache file is within the set update time
* Return: If the contents of the file are returned within the update time, the reverse returns the failure
*/
function Cachecheck () {
if (file_exists ($this->cachefilename)) {
$cTime = $this->getfilecreatetime ($this->cachefilename);
if ($cTime + $this->cachelimittime > Time ()) {
Echo file_get_contents ($this->cachefilename);
Ob_end_flush ();
Exit
}
}
return false;
}

/*
* Cache files or output static
* String $staticFileName static file name (with relative path)
*/
function caching ($staticFileName = "") {
if ($this->cachefilename) {
$cacheContent = Ob_get_contents ();
Echo $cacheContent;
Ob_end_flush ();

if ($staticFileName) {
$this->savefile ($staticFileName, $cacheContent);
}

if ($this->cachelimittime)
$this->savefile ($this->cachefilename, $cacheContent);
}
}

/*
...... Remaining full text >>

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