PHP工具类 MySQL增删改查工具类_MySQL
?php header("content-type:text/html;charset=utf-8"); class DBUtils{ /** *通用更新方法 insert update delete 操作 *@param sql *@return bool true false */ public function update($sql){ $link = $this->getConn(); mysql_query($sql); //如果出错显示 if(DEBUG){ echo mysql_error(); } $rs = mysql_affected_rows($link); $rs = $rs > 0; mysql_close($link); return $rs; } /** *通用查询方法 select 操作 *@param sql *@return array */ public function queryRows($sql){ //创建连接,编码,数据库 $link = $this->getConn(); //发送sql $rs = mysql_query($sql); //如果出错显示 if(DEBUG){ echo mysql_error(); } $rows = array(); while($row = mysql_fetch_array($rs)){ $rows[] = $row;//pdemo7.php } // mysql_free_result($rs); mysql_close($link); return $rows; } /** *通用查询方法 select 操作 查询结果一行数据 *@param sql *@return array 如果失败返回 false; */ public function queryRow($sql){ $rs = $this->queryRows($sql); if(!empty($rs[0])){ return $rs[0]; } return false; } /** *通用查询方法 select 操作 查询结果一个数据 *@param sql *@return array 如果失败返回 false; * 例: select count(*) from user; */ public function queryObj($sql){ $rs = $this->queryRows($sql); //var_dump($rs); if(!empty($rs[0][0])){ return $rs[0][0]; } return false; } private function getConn(){ $link = mysql_connect('127.0.0.1','root',''); mysql_query("set names utf8"); mysql_select_db("news"); return $link; } }

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Using the chrono library in C can allow you to control time and time intervals more accurately. Let's explore the charm of this library. C's chrono library is part of the standard library, which provides a modern way to deal with time and time intervals. For programmers who have suffered from time.h and ctime, chrono is undoubtedly a boon. It not only improves the readability and maintainability of the code, but also provides higher accuracy and flexibility. Let's start with the basics. The chrono library mainly includes the following key components: std::chrono::system_clock: represents the system clock, used to obtain the current time. std::chron

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