php操作mysql与sqlite类
来源：http://www.yytweb.com/?s=article-13.html
源博客上的类，有些小问题(表前缀只对mysql进行了处理，sqlite的没有处理)，下面的这个是我做过一些处理之后的类，我也测试过了，可以使用。感兴趣的朋友也可以继续扩展下。
<?php/** * 文件描述 PDO数据库操作类 * ================================================================= * 作 者 YYT<gyyst@126.com> * ================================================================= */class db{private $config;private $db;public $querynum;public function mysql($host, $user, $password, $dbname, $tablepre = '', $charset = 'GBK'){$this->config['type'] = 'mysql';$this->config['tablepre'] = $tablepre;$this->config['mysql']['host'] = $host;$this->config['mysql']['user'] = $user;$this->config['mysql']['password'] = $password;$this->config['mysql']['dbname'] = $dbname;$this->config['mysql']['charset'] = $charset;}public function sqlite($datafile,$tablepre = ''){$this->config['type'] = 'sqlite';$this->config['sqlite']['file'] = $datafile; $this->config['tablepre'] = $tablepre;}private function connect(){if (isset($this->db)) {return true;}if ($this->config['type'] == 'mysql') {try{$this->db = new PDO('mysql:host='.$this->config['mysql']['host'].';dbname='.$this->config['mysql']['dbname'], $this->config['mysql']['user'], $this->config['mysql']['password'], array(PDO::ATTR_PERSISTENT => true));$this->db->query('SET NAMES '.$this->config['mysql']['charset']);} catch (PDOException $e) {exit('数据库连接失败：'.$e->getMessage());}}if ($this->config['type'] == 'sqlite') {!file_exists($this->config['sqlite']['file']) && exit('没有找到SQLITE数据库');$this->db = new PDO('sqlite:'.$this->config['sqlite']['file']);}!isset($this->db) && exit('不支持该数据库类型 '.$this->config['type']);}public function table($table){return '`'.$this->config['tablepre'].$table.'`';}public function strescape($str){if ($this->config['type'] === 'mysql') {return !get_magic_quotes_gpc() ? addslashes($str) : $str;}if ($this->config['type'] === 'sqlite') {return str_replace('\'', '\'\'', $str);}return $str;}public function format_condition($condition){if (is_array($condition)) {foreach ($condition as $key => $value) {$join[] = $key.' = \''.$this->strescape($value).'\'';}return ' WHERE '.join(' AND ', $join);}return $condition ? ' WHERE '.$condition : '';}private function error(){if ($this->db->errorCode() != '00000') {$error = $this->db->errorInfo();exit('SQL语句错误：'.$error['2']);}}public function query($sql){$this->connect();$result = $this->db->query($sql);$this->error();$result->setFetchMode(PDO::FETCH_ASSOC);$this->querynum++;return $result;}public function exec($sql){$this->connect();$result = $this->db->exec($sql);$this->error();$this->querynum++;return $result;}public function lastinsertid(){return $this->db->lastInsertId();}public function fetchall($table, $field, $condition = '', $sort = '', $limit = ''){$condition = $this->format_condition($condition);$sort && $sort = ' ORDER BY '.$sort;$limit && $limit = ' LIMIT '.$limit;$sql = 'SELECT '.$field.' FROM '.$this->table($table).$condition.$sort.$limit;return $this->query($sql)->fetchall();}public function fetch($table, $field, $condition = '', $sort = ''){$condition = $this->format_condition($condition);$sort && $sort = ' ORDER BY '.$sort;$sql = 'SELECT '.$field.' FROM '.$this->table($table).$condition.$sort.' LIMIT 1';return $this->query($sql)->fetch();}public function rowcount($table, $condition = ''){$condition = $this->format_condition($condition);$sql = 'SELECT COUNT(*) FROM '.$this->table($table).$condition;$result = $this->query($sql)->fetch();return $result['COUNT(*)'];}public function get_fields($table){if ($this->config['type'] == 'mysql') {$sql = 'DESCRIBE '.$this->table($table);$key = 'Field';} else if ($this->config['type'] == 'sqlite') {$sql = 'PRAGMA table_info('.$this->table($table).')';$key = 'name';}$fields = $this->query($sql)->fetchall();foreach ($fields as $value) {$result[] = $value[$key];}return $result;}public function insert($table, $array){if (!is_array($array)) {return false;}foreach ($array as $key => $value) {$cols[] = $key;$vals[] = '\''.$this->strescape($value).'\'';}$col = join(',', $cols);$val = join(',', $vals);$sql = 'INSERT INTO '.$this->table($table).' ('.$col.') VALUES ('.$val.')';return $this->exec($sql);}public function update($table, $array, $condition){if (!is_array($array)) {return false;}$condition = $this->format_condition($condition);foreach ($array as $key => $value) {$vals[] = $key.' = \''.$this->strescape($value).'\'';}$values = join(',', $vals);$sql = 'UPDATE '.$this->table($table).' SET '.$values.$condition;return $this->exec($sql);}public function delete($table, $condition){$condition = $this->format_condition($condition);$sql = 'DELETE FROM '.$this->table($table).$condition;return $this->exec($sql);}}//例子$db = new db();//配置数据库，2选一//$db->mysql($host, $user, $password, $dbname, '表前缀', 'GBK');$db->sqlite('d:\Backup\test2.db');//SQL语句查询$db->query('SELECT * FROM 表')->fetch();//或者fetchall();//执行一条无返回结果的SQL语句，如插入数据$db->exec($sql);//返回最后插入的数据主键echo $db->lastinsertid();/***** 下面的操作如果条件为数组则不需要字符转义 *****///查询一条数据$db->fetch('表', '字段1,字段2', '条件，可用数组，如：array(id => 1)', 'id DESC');//查询所有数据$db->fetchall('表', '字段1,字段2', '条件，可用数组', 'id DESC', '显示条数');//插入一条数据$db->insert('test', array('username' => 'lxx', 'password' => 'lxx'));//更新一条数据$db->update('表', array('字段' => '值', '字段2' => '值'), array('id' => '1 更新ID为1的数据'));//删除一条数据$db->delete('test', array('username' => 'lxx'));