Question

我正在处理一个项目，我想根据用户检查登录凭据。当有新用户登录时，如果用户名存在于数据库中，则会产生错误！

username exist

代码：

include('connect.php'); 

    $query = mysql_query("SELECT * FROM users WHERE user_name = '". $user_name ."' "); 

    if (mysql_num_rows($query) > 0) 
    { 
     echo 'Username already in use please try another.'; 
    }
    else{
    $opt=$obj->addStudent($user_name,$user_pass,$user_email,$user_contact);
    }
}

我想检查忽略区分大小写。

Answer 1

include('connect.php'); 

    $query = mysql_query("SELECT * FROM users WHERE UPPER(user_name) = '". mysql_real_escape_string(strtoupper($user_name)) ."' "); 

    if (mysql_num_rows($query) > 0) 
    { 
     echo 'Username already in use please try another.'; 
    }
    else{
    $opt=$obj->addStudent($user_name,$user_pass,$user_email,$user_contact);
    }
}

这样用户名：XyZ将与xyz相同

Answer 2

使用更快的代码进行唯一名称测试。

include('connect.php'); 

    $query = mysql_query("SELECT `user_name` FROM users WHERE LOWER(user_name) = LOWER(". $user_name .")"); 

    if (mysql_num_rows($query) > 0) 
    { 
     echo 'Username already in use please try another.'; 
    }
    else{
    $opt=$obj->addStudent($user_name,$user_pass,$user_email,$user_contact);
    }

如果存在于数据库中，则username应该是唯一的，然后返回错

2 个答案: