两段代码掌握php session

最近学习session，自己觉得可以通过这两个方法更快的掌握session，通过代码一可以更快的掌握session 6个阶段的执行时机，代码二是简单实现了mysql存储session，

希望对学友有帮助！

代码一，session各阶段运行时机

<?/*Session open (called by session_start( ))Session close (called at page end)Session read (called after session_start( ) )Session write (called when session data is to be written)Session destroy (called by session_destroy( ) )Session garbage collect (called randomly)*/    function sess_open($sess_path, $sess_name) {            print "Session opened.\n";            print "Sess_path: $sess_path\n";            print "Sess_name: $sess_name\n\n";            return true;    }     function sess_close( ) {            print "Session closed.\n";            return true;    }     function sess_read($sess_id) {            print "Session read.\n";            print "Sess_ID: $sess_id\n";            return '';    }     function sess_write($sess_id, $data) {            print "Session value written.\n";            print "Sess_ID: $sess_id\n";            print "Data: $data\n\n";            return true;    }     function sess_destroy($sess_id) {            print "Session destroy called.\n";            return true;    }     function sess_gc($sess_maxlifetime) {            print "Session garbage collection called.\n";            print "Sess_maxlifetime: $sess_maxlifetime\n";            return true;    }     session_set_save_handler("sess_open", "sess_close", "sess_read",                    "sess_write", "sess_destroy", "sess_gc");    //实验开始    /*        开启session，这里首先确认php.ini session.auto_start=0        否则这里是无效的，一般session.auto_start 默认是 0     */    session_start( );      /*        这里可以发现，session写入文件或数据库是在整个文件执行完之后，        在文件执行完之前$_SESSION是存在内存中的     */    $_SESSION['foo'] = "bar";    echo $_SESSION['foo'];    print "Some text\n";    $_SESSION['baz'] = "wombat";?>

代码二，mysql存储session简单实现

<?php # Script 3.1 - db_sessions.inc.php/*  *  This page creates the functional interface for  *  storing session data in a database. *  This page also starts the session. */// Global variable used for the database // connections in all session functions:$sdbc = NULL;// Define the open_session() function:// This function takes no arguments.// This function should open the database connection.// This function should return true.function open_session() {    global $sdbc;    $sdbc = @mysqli_connect('localhost', 'root', 'root', 'session', '3306');    if ($sdbc) {        return true;    } else {        die('mysqli errorcode:'. mysqli_connect_errno() . '<br/> mysqli errormsg: '. mysqli_connect_error().'<br>'. debug_print_backtrace());    }} // End of open_session() function. // Define the close_session() function:// This function takes no arguments.// This function closes the database connection.// This function returns the closed status.function close_session() {    global $sdbc;        return mysqli_close($sdbc);} // End of close_session() function.// Define the read_session() function:// This function takes one argument: the session ID.// This function retrieves the session data.// This function returns the session data as a string.function read_session($sid) {    global $sdbc;    // Query the database:    $q = sprintf('SELECT data FROM sessions WHERE id="%s"', mysqli_real_escape_string($sdbc, $sid));     $r = mysqli_query($sdbc, $q);        // Retrieve the results:    if (mysqli_num_rows($r) == 1) {        list($data) = mysqli_fetch_array($r, MYSQLI_NUM);                // Return the data:        return $data;    } else { // Return an empty string.        return '';    }} // End of read_session() function.// Define the write_session() function:// This function takes two arguments: // the session ID and the session data.function write_session($sid, $data) {    global $sdbc;    // Store in the database:    $q = sprintf('REPLACE INTO sessions (id, data) VALUES ("%s", "%s")', mysqli_real_escape_string($sdbc, $sid), mysqli_real_escape_string($sdbc, $data));     $r = mysqli_query($sdbc, $q);return true;} // End of write_session() function.// Define the destroy_session() function:// This function takes one argument: the session ID.function destroy_session($sid) {    global $sdbc;    // Delete from the database:    $q = sprintf('DELETE FROM sessions WHERE id="%s"', mysqli_real_escape_string($sdbc, $sid));     $r = mysqli_query($sdbc, $q);        // Clear the $_SESSION array:    $_SESSION = array();    return true;} // End of destroy_session() function.// Define the clean_session() function:// This function takes one argument: a value in seconds.function clean_session($expire) {    global $sdbc;    // Delete old sessions:    $q = sprintf('DELETE FROM sessions WHERE DATE_ADD(last_accessed, INTERVAL %d SECOND) < NOW()', (int) $expire);     $r = mysqli_query($sdbc, $q);    return true;} // End of clean_session() function.# **************************** ## ***** END OF FUNCTIONS ***** ## **************************** #// Declare the functions to use:session_set_save_handler('open_session', 'close_session', 'read_session', 'write_session', 'destroy_session', 'clean_session');// Make whatever other changes to the session settings, if you want.// Start the session:session_start();