尝试检查时出错 [英] Error while trying to check

问题描述

我想检查一些事情......但我不能......(检查下面).

i wanna do check for few things.... but i'm not able to...(check below).

好的，所以它是如何工作的，但我想再添加一张支票.

Okey so this works how it is but i wanna add more one check.

mysql_query('UPDATE characters SET voted=1 where account_name like \''.$row['login'].'\' and online=1;') ;

无论如何我要添加的是在 online=1 之后检查在哪里MIN(lastAccess)

Anyway what i wanna add is after online=1 to check where MIN(lastAccess)

我尝试了几件事，但我失败了...喜欢:

I tried few things but i failed... like:

mysql_query('UPDATE characters SET voted=1 where account_name like \''.$row['login'].'\' and online=1 having min(lastaccess);') ;

推荐答案

您甚至可以根据需要进一步加入表格，

You can even further join the tables to work as desired,

UPDATE  characters a
        INNER JOIN
        (
            SELECT  account_name, MIN(lastaccess) min_date
            FROM    characters
            GROUP   BY account_name
        ) b ON  a.Account_Name = b.Account_name AND
                a.lastAccess = b.min_date
SET     a.voted = 1
WHERE   a.Account_Name = 'nameHere' AND
        a.online = 1

更新 1

尝试使用双引号，例如

$userName = $row['login'];
$result = mysql_query(" UPDATE  characters a
                                INNER JOIN
                                (
                                    SELECT  account_name, MIN(lastaccess) min_date
                                    FROM    characters
                                    GROUP   BY account_name
                                ) b ON  a.Account_Name = b.Account_name AND
                                        a.lastAccess = b.min_date
                        SET     a.voted = 1
                        WHERE   a.Account_Name = '$userName' AND
                                a.online = 1");

作为旁注，查询容易受到SQL注入的影响，如果变量的 value(s) 来自外部.请查看下面的文章，了解如何预防.通过使用 PreparedStatements，您可以摆脱在值周围使用单引号.

As a sidenote, the query is vulnerable with SQL Injection if the value(s) of the variables came from the outside. Please take a look at the article below to learn how to prevent from it. By using PreparedStatements you can get rid of using single quotes around values.

• 如何在 PHP 中防止 SQL 注入?

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