本文实例讲述了php实现的pdo公共类定义与用法。分享给大家供大家参考，具体如下：

db.class.php ：

<?phpclass db extends \PDO { private static $_instance = null; protected $dbName = ''; protected $dsn; protected $dbh; public function __construct($dbHost, $dbUser, $dbPasswd, $dbName, $dbCharset='utf8') { try { $this->dsn = 'mysql:host=' . $dbHost . ';dbname=' . $dbName; $this->dbh = new \PDO($this->dsn, $dbUser, $dbPasswd); $this->dbh->setAttribute(\PDO::ATTR_EMULATE_PREPARES, false); $this->dbh->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION); $this->dbh->exec('SET character_set_connection='.$dbCharset.';SET character_set_client='.$dbCharset.';SET character_set_results='.$dbCharset); } catch (Exception $e) { $this->outputError($e->getMessage()); } } public static function getInstance($dbHost, $dbUser, $dbPasswd, $dbName, $dbCharset='utf8') { if (self::$_instance === null) { self::$_instance = new self($dbHost, $dbUser, $dbPasswd, $dbName, $dbCharset); } return self::$_instance; } public function fetchAll($sql, $params = array()) { try { $stm = $this->dbh->prepare($sql); if ($stm && $stm->execute($params)) { return $stm->fetchAll(\PDO::FETCH_ASSOC); } } catch (Exception $e) { $this->outputError($e->getMessage()); } } public function fetchOne($sql, $params = array()) { try { $result = false; $stm = $this->dbh->prepare($sql); if ($stm && $stm->execute($params)) { $result = $stm->fetch(\PDO::FETCH_ASSOC); } return $result; } catch (Exception $e) { $this->outputError($e->getMessage()); } } public function fetchColumn($sql, $params = array()) { $result = ''; try { $stm = $this->dbh->prepare($sql); if ($stm && $stm->execute($params)) { $result = $stm->fetchColumn(); } return $result; } catch (Exception $e) { $this->outputError($e->getMessage()); } } public function insert($table, $params = array(), $returnLastId = true) { $_implode_field = ''; $fields = array_keys($params); $_implode_field = implode(',', $fields); $_implode_value = ''; foreach ($fields as $value) { $_implode_value .= ':'. $value.','; } $_implode_value = trim($_implode_value, ','); $sql = 'INSERT INTO ' . $table . '(' . $_implode_field . ') VALUES ('.$_implode_value.')'; try { $stm = $this->dbh->prepare($sql); $result = $stm->execute($params); if ( $returnLastId ) { $result = $this->dbh->lastInsertId(); } return $result; } catch (Exception $e) { $this->outputError($e->getMessage()); } } public function update($table, $params = array(), $where = null) { $_implode_field = ''; $_implode_field_arr = array(); if ( empty($where) ) { return false; } $fields = array_keys($params); foreach ($fields as $key) { $_implode_field_arr[] = $key . '=' . ':'.$key; } $_implode_field = implode(',', $_implode_field_arr); $sql = 'UPDATE ' . $table . ' SET ' . $_implode_field . ' WHERE ' . $where; try { $stm = $this->dbh->prepare($sql); $result = $stm->execute($params); return $result; } catch (Exception $e) { $this->outputError($e->getMessage()); } } public function delete($sql, $params = array()) { try { $stm = $this->dbh->prepare($sql); $result = $stm->execute($params); return $result; } catch (Exception $e) { $this->outputError($e->getMessage()); } } public function exec($sql, $params = array()) { try { $stm = $this->dbh->prepare($sql); $result = $stm->execute($params); return $result; } catch (Exception $e) { $this->outputError($e->getMessage()); } } private function outputError($strErrMsg) { throw new Exception("MySQL Error: " . $strErrMsg); } public function __destruct() { $this->dbh = null; }}

实例：

<?phprequire_once './db.class.php';$pdo = db::getInstance('127.0.0.1', 'root', '111111', 'php_cms');$sql = "select id, title1 from cms_wz where id = :id limit 1";$parame = array('id' => 12,);$res = $pdo->fetchOne($sql, $parame);var_dump($res);$sql = 'SELECT * FROM cms_link';$result = $db->fetchAll($sql);print_r($result);//查询记录数量$sql = 'SELECT COUNT(*) FROM cms_link';$count = $db->fetchColumn($sql);echo $count;$data = array( 'siteid' => 1, 'linktype' => 1, 'name' => 'google', 'url' => 'http://', 'listorder' => 0, 'elite' => 0, 'passed' => 1, 'addtime' => time() );$db->insert('cms_link', $data);$sql = 'DELETE FROM cms_link WHERE linkid=4';$result = $db->delete($sql);var_dump($result);

更多关于PHP相关内容感兴趣的读者可查看本站专题：《PHP基于pdo操作数据库技巧总结》、《php+Oracle数据库程序设计技巧总结》、《PHP+MongoDB数据库操作技巧大全》、《php面向对象程序设计入门教程》、《php字符串(string)用法总结》、《php+mysql数据库操作入门教程》及《php常见数据库操作技巧汇总》

希望本文所述对大家PHP程序设计有所帮助。