How to operate session and database in php-PHP Tutorial-php.cn

This article mainly introduces the method of operating session and database in PHP. Interested friends can refer to it. I hope it will be helpful to everyone.

The example in this article describes how PHP uses MySQL to save sessions. The specific analysis is as follows:

This function is generally available in many large systems, but it must be separated and analyzed, and the information on the Internet There are not too many. Here I compiled an article to share with you

Using MySQL to save sessions has many advantages over files:

1) It is beneficial to distributed systems, files can only be saved On one machine
2) It is beneficial to systems with large traffic. When using files, each session is saved in a file. The directory will be very large and it will be difficult to find the session file.

To use MySQL to save a session, you must first create the session table:

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MysqlSession class is as follows:

DB_NAME = &$sessionDB; $this->SESS_LIFE = get_cfg_var("session.gc_maxlifetime"); session_module_name('user'); session_set_save_handler( array(&$this, 'sess_open'), array(&$this, 'sess_close'), array(&$this, 'sess_read'), array(&$this, 'sess_write'), array(&$this, 'sess_destroy'), array(&$this, 'sess_gc') ); session_start(); } function sess_open($save_path, $session_name){ // 打开数据库连接 if (! $this->DB_SELECT_DB = mysql_pconnect($this->DB_SERVER, $this->DB_USER, $this->DB_PASS)) { echo "SORRY! MYSQL ERROR : Can't connect to $this->DB_SERVER as $DB_USER"; echo "MySQL Error: ", mysql_error(); die; } if (! mysql_select_db($this->DB_NAME, $this->DB_SELECT_DB)) { echo "SORRY! MYSQL ERROR : Unable to select database $this->DB_NAME"; die; } return true; } function sess_close() { return true; } function sess_read($SessionKey){ $Query = "SELECT SessionArray FROM sessions WHERE SessionKey = '".$SessionKey."' AND SessionExpTime > " . time(); // 过期不读取。 $Result = mysql_query($Query, $this->DB_SELECT_DB); if (list($SessionArray) = mysql_fetch_row($Result)) { return $SessionArray; } return false; } function sess_write($SessionKey, $VArray) { $SessionExpTime = time() + $this->SESS_LIFE; // 更新Session过期时间，Session过期时间 = 最后一次更新时间 + Session的最大使用时长 $SessionArray = addslashes($VArray); $Query = "INSERT INTO sessions (SessionKey,SessionExpTime,SessionArray) VALUES ('".$SessionKey."','".$SessionExpTime."','".$SessionArray."')"; $Result = mysql_query($Query, $this->DB_SELECT_DB); if (!$Result){ $Query = "UPDATE sessions SET SessionExpTime = '".$SessionExpTime."', SessionArray = '".$SessionArray."' WHERE SessionKey = '".$SessionKey."' AND SessionExpTime > " . time(); $Result = mysql_query($Query, $this->DB_SELECT_DB); } return $Result; } function sess_destroy($SessionKey) { $Query = "DELETE FROM sessions WHERE SessionKey = '".$SessionKey."'"; $Result = mysql_query($Query, $this->DB_SELECT_DB); return $Result; } function sess_gc($maxlifetime) { // 这个垃圾清除器系统调用。默认是1440秒清除一次。 //参数可以在PHP.ini里面设置。 $Query = "DELETE FROM sessions WHERE SessionExpTime < " . time(); $Result = mysql_query($Query, $this->DB_SELECT_DB); return mysql_affected_rows($this->DB_SELECT_DB); } } ?>

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Usage: Where session_start was originally used, replace it with $session = new MysqlSession ()

Note: The database must be opened before including this program. The database cannot be closed before the main program exits, otherwise an error will occur.

Summary:The above is the entire content of this article, I hope it will be helpful to everyone's study.

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