分享一个现在使用的PDO

1.dbbase .php

<?phpdefine('DB_SERVER','mysql');define('DB_HOST','localhost');define('DB_USERNAME','root');define('DB_PASSWD','root');define('DB_NAME','test');require_once('DB.php');if(!isset($_SESSION))session_start();if(!isset($_SESSION['ID']) || $_SESSION['ID']==''){header('location:login.php');exit;}?>

2..DB.php

<?php/** * Database abstraction class, make very easy to work with databases. * Created : 2009 - March - 05 * @author Gombos Lorand ([e-mail]) * @name simpleSQL - PDO * @version 1.1 * Updated by ck87801 ([e-mail]) 2009-04-03 *//** * Database specific class - mySQL * */class DB {/** * Host name. * @see connect() * @var string */private  $hostname=DB_HOST;/** * Database username. * @see connect() * @var string */private  $username=DB_USERNAME;/** * User password for database. * @var string */private  $password=DB_PASSWD;/** * Database name. * @see connect() * @var string */private $dbname=DB_NAME;/** * Represented the DD class instance. * Help to implement the Singleton design pattern. * @var boolean|object DB */private  $instance = FALSE;/** * PDO fetch mode. * This variable use we to setting the PDO fetching mode. * @var string */public $fetch_mode = PDO::FETCH_ASSOC;/** * Last query, used by this class. * @var string */private $last_query= NULL;/** * After we execute the last query, we obtain a PDO statement. * @var PDO::Statement */private $last_statement = NULL;/** * Contain the last result. * @var array|object */private $last_result= NULL;/** * Row count, returned by last query. * @var integer */private $row_count= NULL;/** * Affected row, returned by last query (DML Queryes). * @var integer */private $affected_row= NULL;public $debug = true;/** * Constructor. * Implements the Singleton design pattern. * * @return object DB * @access public * @uses connect() connect to database. */public function __construct() {if (!$this->instance){$this->connect();$this->query('set names utf8');}return $this->instance;}/** * Destructor * frees up the connection to the server so that other SQL statements may be issued, but leaves the statement in * a state that enables it to be executed again */public function __destruct (){$this->instance = null;}/** * Connect to the database and set the error mode to Exception. * * @return void * @access private */private function connect(){$dns = DB_SERVER.':host='.$this->hostname.';dbname='.$this->dbname;    $this->instance = new PDO($dns, $this->username, $this->password);}/** * Select a database. * * @param string $dbname * @return void * @access public */public function selectDB($dbname){$this->dbname = $dbname;$this->connect();}/** * Execute a query. * This function can be used from external. * The function separate the simple queryes and the INSERT, UPADTE, DELETE queries. * Do not use this function without escape the data with function DB::escape * * @param string $query * @return result/affected row depending on query type. * @access public */public function query($query = NULL){$this->flush();$query = trim($query);$this->last_query = $query;// Query was an insert, delete, update, replaceif ( preg_match("/^(insert|delete|update|replace|drop|create|truncate)\\s+/i",$query) ){$this->affected_row = $this->instance->exec($query);if ( $this->catch_error() ) return false;else return $this->affected_row;}else {//Query was an simple query.$stmt = $this->instance->query($query);if ( $this->catch_error() ) return false;else {$stmt->setFetchMode($this->fetch_mode);$this->last_statement = $stmt;$this->last_result = $this->last_statement->fetchAll();return $this->last_result;}}}/** * Execute a query. * This function can be used from DB class methods. * * @param string $query * @return bool * @access private */private function internalQuery($query = NULL){$this->flush();$query = trim($query);$this->last_query = $query;$stmt = $this->instance->query($query);if ( $this->catch_error() ) return false;$stmt->setFetchMode($this->fetch_mode);$this->last_statement = $stmt;return TRUE;}/** * Execute a query (INSERT, UPDATE, DELETE). * This function can be used from DB class methids. * * @param string $query * @return int * @access private */private function execute($query = NULL){$this->flush();$query = trim($query);$this->last_query = $query;$this->affected_row = $this->instance->exec($query);if ($this->catch_error()) return false;return $this->affected_row;}/** * Return a result set. * * @param string $query * @return result set * @access public. */public function getResults($query = NULL){$this->internalQuery($query);$result = $this->last_statement->fetchAll();$this->last_result = $result;return $result;}/** * Get one row from the DB. * * @param string $query * @return reulst set * @access public */public function getRow($query = NULL){$this->internalQuery($query);$result = $this->last_statement->fetch();$this->last_result = $result;return $result;}/** * Helper function, walk the array, and modify the values. * * @param pointer $item * @return void * @access private */private function prepareDbValues(&$item){$item = $this->instance->quote($this->escape($item));}/** * Insert a value into a table. * * @param string $table * @param array $data * @return integer * @access public */public function insert($table = NULL, $data = NULL){array_walk($data,array($this,'prepareDbValues'));$query = "INSERT INTO `".$table."` (`".implode('`, `', array_keys($data))."`) VALUES ( ".implode(', ', $data).")";return $this->execute($query);}/** * Update a value(s) in a table * Ex: * $table = 'tableName'; * $data = array('text'=> 'value', 'date'=> '2009-12-01'); * $where = array('id=12','AND name="John"'); OR $where = 'id = 12'; * * @param string $table * @param array $data * @param array/string $where * @return void * @access public */public function update($table = NULL, $data = NULL, $where = NULL){array_walk($data,array($this,'prepareDbValues'));foreach ($data as $key => $val){$valstr[]= '`'.$key.'` = '.$val;}$query = "UPDATE `".$table."` SET ".implode(', ', $valstr);if (is_array($where)){$query.= " WHERE ".implode(" ",$where);}else {$query.= " WHERE ".$where;}return $this->execute($query);}/** * Delete a record from a table. * Ex. * $table = 'tableName'; * $where = array('id = 12','AND name = "John"'); OR $where = 'id = 12'; * * @param string $table * @param array/string $where * @return void * @access public */public function delete($table = NULL, $where = NULL){$query = "DELETE FROM `".$table."` WHERE ";if (is_array($where)){$query.= implode(" ",$where);}else{$query.= $where;}return $this->execute($query);}/** * Return  a result set. * Similar to {@link getResults()}, but in this case not need to write a query. * The generated query is based on $where associative Array and $table. * * Ex. * <code> * $where = array(); * $where['username'] = 'testUsername'; * $where['id'] = '1'; * $result =  $c->buildQuery('user',$where); * print_r($result); * </code> * * @param string $table * @param array $where * @return array - result set * @access public */public function buildQuery($table,$where){array_walk($where,'DB::prepareDbValues');$query = "SELECT * FROM `{$table}` WHERE ";$valstr = array();foreach ($where as $key => $value){$valstr[] = "`{$key}` = {$value}";}$query.= implode(" AND ",$valstr);$this->internalQuery($query);$result = $this->last_statement->fetchAll();$this->last_result = $result;return $result;}/** * Return the last insert id. * * @return integer * @access public */public function getLastInsertId(){return $this->instance->lastInsertId();}/** * Return the last executed query. * * @return string * @access public */public function getLastQuesry(){return $this->last_query;}/** * Returns the number of rows affected by the last SQL statement. * * @return int * @access public */public function getRowCount(){if (!is_null($this->last_statement)){return $this->last_statement->rowCount();}else {return 0;}}/** * Set the PDO fetch mode. * * @param string $fetch_mode * @return void * @access public */public function setFetchMode($fetch_mode){$this->fetch_mode = $fetch_mode;}/** * Set to NULL all cached data. * * @return void * @access private */private function flush(){$this->last_query= NULL;$this->last_statement = NULL;$this->last_result= NULL;$this->row_count= NULL;$this->affected_row= NULL;}/***  Format a mySQL string correctly for safe mySQL insert*  (no mater if magic quotes are on or not)** @param string $str* @return string* @access public*/public function escape($str){return mysql_escape_string(stripslashes($str));}/** * Print the error if exist. * * @return vois * @access private */private function catch_error(){$err_array = $this->instance->errorInfo();// Note: Ignoring error - bind or column index out of rangeif ( isset($err_array[1]) && $err_array[1] != 25){try {throw new Exception();}catch (Exception  $e){if($this->debug==true){print "<div style='background-color:#D8D8D8; color:#000000; padding:10px;border:2px red solid;>";print "<p style='font-size:25px; color:#7F0000'>DATABASE ERROR</p>";print "<p style='font-size:20px; color:#7F0000'>Query:<br /><span style='font-size:15px; color:#000000;'>{$this->getLastQuesry()}</span></p>";print "<p style='font-size:20px; color:#7F0000'>Message:<br /><span style='font-size:15px; color:#000000;'>{$err_array[2]}</span></p>";print "</div>";die();}}return TRUE;}else {return FALSE;}}/** * Get one field from a table of the DB. * * @param string $table,$feild,$conditions * @return string or bool * @access public */public function getFeild($table,$feild,$conditions){$this->internalQuery("select $feild from $table where $conditions");$result = $this->last_statement->fetch();if($result){return $result[$feild];}else{return false;}}/** * Get the next record's ID of the table * * @param string $table,$feild_primary * @return string * @access public */public function getNextID($table,$feild_primary){$this->internalQuery("select $feild_primary from $table order by $feild_primary desc limit 1");$result = $this->last_statement->fetch();if($result){return $result[$feild_primary]+1;}else{return false;}}}?>

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