用户注册php

Question

<?php
include"include/connection.php";

$checkusername=mysql_query("SELECT * FROM employer WHERE eusername='$username'");
if (mysql_num_rows($checkusername)==1)
{
  echo "username already exist";
}
else
{
  $query = "insert into employer(efname,elname,egender,eemail,eusername,epwd,eadd,ephone,ecity,ecountry) values ('".$_POST['first_name']."','".$_POST['last_name']."','".$_POST['gender']."','".$_POST['email']."','".$_POST['username']."','".$_POST['password']."','".$_POST['address']."','".$_POST['phone']."','".$_POST['city']."','".$_POST['country']."')";
  $result = mysql_query($query) or die (mysql_error());
  echo " Thanks for registration";
}
?>

这是我将注册表单数据插入数据库的代码.此代码添加数据但也提供解析错误,但如果用户名已存在则不会给出错误.

Notice: Undefined variable: username in C:\Program Files\EasyPHP5.3.0\www\register_hirer2.php on line 6
Thanks for registration 

第6行是:

 $checkusername=mysql_query("SELECT * FROM employer WHERE eusername='$username'");

Answer 1

嗯,你$username确实是不确定的.

很可能你想用$_POST['username'].

当然这是强制性的XKCD漫画: