<?php class 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：
<?php require_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://www.google.com', 'listorder' => 0, 'elite' => 0, 'passed' => 1, 'addtime' => time() ); $lastInsertId = $db->insert('cms_link', $data); echo $lastInsertId; //用 try try { $result = $pdo->insert('news', $essay); } catch (Exception $e) { error_log($e->getMessage()); error_log($e->getMessage() . ' in ' . __FILE__ . ' on line ' . __LINE__); saveLog('url文章 : ' . $essay['link'] . ' 数据插入失败<br>'); continue; } $data = array( 'siteid' => 1, 'linktype' => 1, 'name' => 'google', 'url' => 'http://www.google.com', '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);