php+mysqli预处理技术实现添加、修改及删除多条数据的方法_PHP
本文实例讲述了php+mysqli预处理技术实现添加、修改及删除多条数据的方法。分享给大家供大家参考。具体分析如下:
首先来说说为什么要有预处理(预编译)技术?举个例子:假设要向数据库添加100个用户,按常规思路,就是向数据库发送100个执行请求,此时,按照 mysql 数据库的工作原理,它需要对每一条执行语句进行编译(这里就有100次)。所以,这里的效率是非常低的。
预处理(预编译)技术的作用,就是减少编译的次数和时间,以提高效果。通过一个案例来说明,预处理(预编译)技术是如何做到的(好吧,先说清楚,当 php 程序第一次发送 sql 语句时,mysql 数据库就编译好,到了后面99次,php只要发送数据过去即可,不需要再进行编译)。
<?php //1、创建数据库连接对象 $mysqli = new MySQLi("localhost","root","123456","liuyan"); if($mysqli->connect_error){ die($mysqli->connect_error); } $mysqli->query("set names 'GBK'"); //2、创建预编译对象 $sql = "insert into account(id,balance) values(?,?)"; //这里用 ? 来代替要插入的数据值 $stmt = $mysqli->prepare($sql); //返回一个statement对象,对象中的方法见手册 MySQLi_STMT //3、绑定参数(需要插入的数据),并执行 $id=null;//这里我数据库设置成了 primary key auto_increment $balance=100.5; $stmt->bind_param("id",$id,$balance); //绑定参数,返回值为布尔值。"if"按顺序代表插入数据的数据类型 //这里$id为int,用i表示,$balance为float型,用d表示,具体见手册 $res = $stmt->execute();//执行语句,返回值为布尔类型 //4、判断是否执行成功 if(!$res){ echo "数据插入失败,balance值为:".$balance; }else{ echo "成功"; } /* *****插入第二条数据 */ //3、绑定参数(需要插入的数据),并执行 $id=null;//这里我数据库设置成了 primary key auto_increment $balance=400.3; $stmt->bind_param("id",$id,$balance); //绑定参数,返回值为布尔值。"if"按顺序代表插入数据的数据类型 //这里$id为int,用i表示,$balance为float型,用d表示。 $res = $stmt->execute();//执行语句,返回值为布尔类型 //4、判断是否执行成功 if(!$res){ echo "数据插入失败,balance值为:".$balance; }else{ echo "成功"; } ?>
希望本文所述对大家的php程序设计有所帮助。

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