PHP 基于PDO封装CURD，分页类封装

<?phpclass mysql_pdo{ ???private $_host; ???private $_user; ???private $_pwd; ???private $_dbname; ???private $_pdo; ???private $_fields; ???private $_values; ???private $_array; ???private $curr_page = 1; ???private $count_page; ???private $each_page = 10; ???private $field_page = ‘*‘; ???private static $connection = null; ???private function __construct () ???{ ???????// 防止实例化 ???} ???/* ???????@@ 入口方法 ???????parameter null ???*/ ???public static function _interance () ???{ ???????// 由于本地$pwd为空所有不判断$pwd; ???????if (is_null(self::$connection)) self::$connection = new mysql_pdo(); ???????return self::$connection; ???} ???/* ???????@@ 设置连接属性 ???????parameter $host 127.0.0.1, $user root, $pwd null, $dbname eatble. ???*/ ???public function _setdata ($host, $user, $pwd, $dbname) ???{ ???????????$this->_host = $host; ???????????$this->_user = $user; ???????????$this->_pwd = $pwd; ???????????$this->_dbname = $dbname; ???????????$this->_connect(); ???} ???/* ???????@@ connection db ???????parameter null. ???*/ ???public function _connect () ???{ ???????try { ???????????$_pdo = new PDO(‘mysql:host=‘. $this->_host .‘;dbname=‘ .$this->_dbname, $this->_user, $this->_pwd); ???????????$_pdo->exec("SET NAMES utf8"); ???????} catch (PDOException $e) { ???????????die("Connection fail:" . $e->getMessage()); ???????} ???????// 把$_pdo这个句柄放在静态属性，方便以下方法调用 ???????self::$connection = $_pdo; ???} ???/* ???????@@ update data ???????@@param $table 表格 ???????@@param $fields 字段名 关联数组 ???????@@param $where 条件 ???????return 受影响的行数 ???*/ ???public function _update ($table, $fields, $where = null) ???{ ???????$fields_key = implode(array_keys($fields)); ???????$fields_value = implode(array_values($fields)); ???????$sql = "update {$table} set {$fields_key} = ‘{$fields_value}‘ " . ($where==null?null: "where " .$where); ???????return self::$connection->exec($sql); ???} ???/* ???????@@ insert data ???????@@param $table 表格 ???????@@param $array 关联数组 ???*/ ???public function _insert ($table, array $array) ???{ ???????$this->_array = $array; ???????$this->foreachstr(); ???????$sql = "insert into {$table} ($this->_fields) values (‘{$this->_values}‘)"; ???????return self::$connection->exec($sql); ???} ???/* ???????@@ select data ???????@param $table 表格 ???????@param $field string field,field2,field3, ???????@param $where array 一维关联数组 default null; ???????@result_type ?PDO::FETCH_BOTH 关联加索引 PDO::FETCH_NUM 索引 default PDO::FETCH_ASSOC 关联 ???*/ ???public function _select ($table, $fields = ‘*‘, $where = null, $result_type = PDO::FETCH_ASSOC) ???{ ???????if ($fields == ‘*‘ and $where == null) { ???????????$sql = "select {$fields} from {$table} " . ($where==null?null:"where ".$where); ???????????$stmt = self::$connection->prepare($sql); ???????????$stmt->execute(); ???????????while ($row = $stmt->fetch($result_type)) { ???????????????$rows[] = $row; ???????????} ???????????return $rows; ???????} ???????if ($where != null) { ???????????if (!is_array($where)) return false; ???????????// 赋值给定义的属性交给以下foreacharray处理，返回的是一个字符串 ???????????$this->_array = $where; ???????????$where = $this->foreacharray(); ???????????if ($where) { ???????????????$sql = "select {$fields} from {$table} ". ($where==null?null:"where ".$where); ???????????????$stmt = self::$connection->prepare($sql); ???????????????$stmt->execute(); ???????????????while ($row = $stmt->fetch($result_type)) { ???????????????????$rows[] = $row; ???????????????} ???????????} ???????????return $rows; ???????} ???} ???/* ???????@查询表格中数据的条数 ???????@param $table 表格 ???????@param $where 关联数组 ???????@return 查询到的数量 number ???*/ ???public function _selectnum ($table, $where = null) ???{ ???????$sql = ‘‘; ???????if (is_null($where)) { ???????????$sql .= "select count(*) from {$table}"; ???????} else { ???????????$this->_array = $where; ???????????$where = $this->foreacharray(); ???????????$sql .= "select count(*) from {$table} " .($where==null?null:"where ".$where); ???????} ???????$stmt = self::$connection->prepare($sql); ???????$stmt->execute(); ???????$row_count = $stmt->fetch(); ???????return $row_count[0]; ???} ???/* ???????@@ delte data ???????@$table 表格 ???????@$where array default null ???????@return 受影响的行数 ???*/ ???public function _delete ($table, $where = null) ???{ ???????if (is_null($where)) return false; ?????// 防止误删表 ???????if (!is_array($where)) return array(); ???????$this->_array = $where; ???????$where = $this->foreacharray(); ???????$sql = "delete from {$table} " . ($where==null?null:"where " . $where); ???????return self::$connection->exec($sql); ???} ???/* ???????@@ 分割数组为字符串 ???????@@param $array 一维关联数组 ???????@$this->_fields field1, field2, field3. ???????@$this->_values ‘values1‘, ‘values2‘, ‘values3‘; ???*/ ???protected function foreachstr () ???{ ???????if (!is_array($this->_array)) return false; ???????$fields = ‘‘; ???????$values = ‘‘; ???????foreach ($this->_array as $key => $val) { ????????????$fields .= $key.‘,‘; ????????????$values .= $val.‘,‘; ???????} ???????$this->_fields = rtrim($fields, ‘,‘); ???????$this->_values = str_replace(‘,‘, ‘\‘,\‘‘, rtrim($values, ‘,‘)); ???} ???/* ???????@@ 将关联数组转换为带有and的字符串 ???????@@param $array 关联数组 ???*/ ???protected function foreacharray () ???{ ???????if (!is_array($this->_array)) return false; ???????$str = ‘‘; ???????foreach ($this->_array as $key => $val) { ???????????if ($key == $val) return false; ????????// 防止sql注入 ???????????$str .= $key .‘ = ‘. "‘$val‘".‘ and ‘; ???????} ???????return substr($str, 0, strrpos($str, ‘and‘)); ???} ???/* ???????@@ 每页显示的数据 ???????@param $table 表格 ???????@param $field 要查询的字段 ?string field1, fiedl2, field3, default * ???????@param $curr_page 当前页码 ???????@param $each_page 自定义每页数据 default 10 ???????@param $where 条件 ???????@return $page ?array 关联数组 ???*/ ???public function _showpage ($table, $field_page = null, $curr_page = null, $each_page = null, $where = null) ???{ ???????if (is_null($field_page)) $field_page = $this->field_page; ???????$this->count_page = $this->_selectnum($table); ?????// 直接调用 _selectnum 拿到总条数 ???????if (is_null($each_page)) $each_page = $this->each_page; ????// 如果$each_page 为空则使用默认的$each_page default 10 ???????// 防止输入错误的当前页导致当前页参数无效 ???????if (is_null($curr_page) || $curr_page > ceil($this->count_page/$each_page) || $curr_page <= 0) $curr_page = $this->curr_page; ???????if (!is_null($where)) { ???????????$this->_array = $where; ???????????$where = $this->foreacharray(); ???????} ???????$curr_page = ($curr_page-1)*$each_page; ???????$count_page = ceil($this->count_page/$each_page); ???????$sql = "select {$field_page} from {$table} " .($where==null?null:"where ". $where). " limit {$curr_page}, {$each_page}"; ?// sql注入会让这里多一个where ???????$stmt = self::$connection->prepare($sql); ???????$stmt->execute(); ???????$pages = []; ???????while ($page = $stmt->fetch(PDO::FETCH_ASSOC)) { ???????????$pages[] = $page; ???????} ???????$this->count_page = $count_page; ???????if ($pages == null) return false; ???????return $pages; ???} ???/* ???????@下一页 ???????@param $table 表格 ???????@param $field_page 要查询的字段 ???????@param $curr_page 条件不符合时调用的是第一页的数据 ???????@return array 二维关联数组 ???*/ ???public function _nextpage ($table, $field_page, $curr_page = null) ???{ ???????$curr_page<$this->count_page?$this->curr_page+=1:$this->curr_page=1; ???????$result = $this->_showpage($table, $field_page, $curr_page); ???????return $result; ???} ???/* ???????@上一页 ???????@param $table 表格 ???????@param $field_page 要查询的字段 ???????@param $curr_page 默认为空时调用的是第一页的数据 ???????@return array 二维关联数组 ???*/ ???public function _prevpage ($table, $field_page, $curr_page = null) ???{ ???????$result = $this->_showpage($table, $field_page, $curr_page); ???????$curr_page>=0?$this->curr_page-=1:$this->curr_page=$this->count_page; ???????return $result; ???} ???/* ???????@总页数 ???????@ param $table 表格 ???????@ return 总页数 ???*/ ???public function _showcount ($table) ???{ ???????$this->_showpage($table); ???????return $this->count_page; ???}}