频道导航

• ▸ PHP
• ▸ Java
• ▸ Java SE
• ▸ Python
• ▸ C#
• ▸ C&C++
• ▸ Ruby
• ▸ VB
• ▸ asp.Net
• ▸ Go
• ▸ Perl
• ▸ netty
• ▸ Django
• ▸ Delphi
• ▸ Jsp
• ▸ .NET Core
• ▸ Spring
• ▸ Flask
• ▸ Springboot
• ▸ SpringMVC
• ▸ Lua
• ▸ Laravel
• ▸ Mybatis
• ▸ Asp
• ▸ Groovy
• ▸ ThinkPHP
• ▸ Yii
• ▸ swoole
• ▸ HTML
• ▸ HTML5
• ▸ JavaScript
• ▸ CSS
• ▸ jQuery
• ▸ Bootstrap
• ▸ Angularjs
• ▸ TypeScript
• ▸ Vue
• ▸ Dojo
• ▸ Json
• ▸ Electron
• ▸ Node.js
• ▸ extjs
• ▸ Express
• ▸ XML
• ▸ ES6
• ▸ Ajax
• ▸ Flash
• ▸ Unity
• ▸ React
• ▸ Flex
• ▸ Ant Design
• ▸ Web前端
• ▸ 微信小程序
• ▸ 微信公众号
• ▸ iOS
• ▸ Android
• ▸ Swift
• ▸ Hybrid
• ▸ Cocos2d-x
• ▸ Flutter
• ▸ Xcode
• ▸ Silverlight
• ▸ cocoa
• ▸ Cordova

• 前端之家
• PHP
• 检查用户名是否已在mysql中存在的php写法

<div class="codebody" id="code58782">
$username=$_REQUEST['username'];
$password=$_REQUEST['password'];
echo "
excute the insertUserInfo";
$con=MysqLi_connect("localhost","root","","my_db");
$sql="SELECT * FROM user WHERE username='$username'"; ho "
this username aready exists"; } else { $sql="INSERT INTO user (username,password) VALUES ('$username','$password')"; if(!MysqLi_query($con,$sql)) { echo "
Error".MysqLi_error($con); } else { echo "
one record added"; } }