php - MYSQL 表对字段挑剔？

Question

我再次遇到 php 和 mysql 问题。我有一个包含用户表的数据库设置，我想创建一个 SELECT COUNT(*) FROM users WHERE {value1} {value2} 等...但问题是我想要的 3 个字段要比较的表中的顺序不正确，并且在尝试 SELECT 查询时，结果 vairable($result) 未正确返回 (!$result)。有没有办法检查 mysql 表中的多个字段，它们之间有字段？这是我想要完成的示例: 名为 users 的 mysql 表包含以下字段:a、b、c、d、e、f、g、h、i、j、k、l 和 m。 我想创建一个 SELECT COUNT(*) FROMusersWHERE a='$_SESSION[user]' and d='$_SESSION[actcode]' and j='$_SESSION[email ]' 但引号中的语句是我的查询，它总是执行 if (!$result) { error("An error has occurred in processing your request."); 语句.我究竟做错了什么？相反，每当我尝试只使用一个字段的语句时，ex a，代码工作正常!这是一个我似乎无法解决的恼人问题!我已经发布了下面的代码，还要注意错误函数是我制作的自定义函数并且工作正常。

<?php
include "includefunctions.php";
$result = dbConnect("program");
if (!$result){
    error("The database is unable to process your request at this time. Please try again later.");

} else {

ob_start();
session_start();
if (empty($_SESSION['user']) or empty($_SESSION['password']) or empty($_SESSION['activationcode']) or empty($_SESSION['email'])){
    error("This information is either corrupted or was not submited through the proper protocol. Please check the link and try again!");
} elseif ($_SESSION['password'] != "password"){
     error("This information is either corrupted or was not submited through the proper protocol. Please check the link and try again!");
} else {

    $sql = "SELECT * FROM `users` WHERE `username`='$_SESSION[user]' and `activationcode`='$_SESSION[activationcode]' and `email`='$_SESSION[email]'";/*DOES NOT MATTER WHAT ORDER THESE ARE IN, IT STILL DOES NOT WORK!*/
    $result = mysql_query($sql);
    if (!$result) {
        error("A database error has occurred in processing your request. Please try again in a few moments.");/*THIS IS THE ERROR THAT WONT GO AWAY!*/
    } elseif (mysql_result($result,0,0)==1){/*MUST EQUAL 1 OR ACCOUNT IS INVALID!*/
        echo "Acount activated!";
    } else {
            error("Account not activated.");    
    }
}
}
ob_end_flush();
session_destroy();
?>

Answer 1

尝试将您的 $_SESSION 变量括在大括号 {} 中，并将 or die(mysql_error()) 添加到查询的末尾-

$sql = "SELECT * FROM `users` WHERE `username`='{$_SESSION['user']}' and `activationcode`='{$_SESSION['activationcode']}' and `email`='{$_SESSION['email']}'";/*DOES NOT MATTER WHAT ORDER THESE ARE IN, IT STILL DOES NOT WORK!*/
$result = mysql_query($sql) or die(mysql_error());