php pdo public class definition and usage example sharing-PHP Tutorial-php.cn

This article mainly introduces the definition and usage of the PDO public class implemented by PHP. It analyzes the PDO operation class definition and query, insertion and other usage techniques implemented by PHP based on specific examples. Friends who need it can refer to it. I hope it can help. Everyone.

db.class.php：

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; } }

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Example:

 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
'); 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);

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PHP's detailed explanation of PDO

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