<?php header("Content-Type:text/html;charset=utf-8"); $mysqli=new mysqli("localhost","root","","test"); if(mysqli_connect_errno()) { printf("连接失败:%s<br>",mysqli_connect_error()); exit(); } $success=TRUE; $price=8000; $result=$mysqli->query("select cash from account where"); while($row=$result->fetch_assoc()) { $value=$row["cash"]; echo $value; } $mysqli->autocommit(0); if($value>=$price){ $result=$mysqli->query("UPDATE account set cash=cash-$price where"); }else { echo '余额不足'; exit(); } if(!$result or $mysqli->affected_rows!=1) { $success=FALSE; } $result=$mysqli->query("UPDATE account set cash=cash+$price where"); if(!result or $mysqli->affected_rows!=1){ $success=FALSE; } if($success) { $mysqli->commit(); echo '转账成功!'; }else { $mysqli->rollback(); echo "转账失败!"; } $mysqli->autocommit(1); $query="select cash from account where name=?"; $stmt=$mysqli->prepare($query); $stmt->bind_param('s',$name); $name='userA'; $stmt->execute(); $stmt->store_result(); $stmt->bind_result($cash); while($stmt->fetch()) echo "用户userA的值为：".$cash; $mysqli->close(); ?>
数据库SQL语句如下：
create table account{ userID smallint unsigned not null auto_increment, name varchar(45) not null, cash decimal(9,2) not null, primary key(userID) )type=InnoDB; insert into account(name,cash) values ('userA','2000'); insert into account(name,cash) values ('userB','10000');