PHP SQL计数查询匹配数

Question

我如何计算与两个变量匹配的行数？

我有一个名为:users的表

和字段调用:用户名和推荐

我有另一个名为:comments的表

和字段调用:comment_username

在这种情况下,我需要获取特定用户引用的至少10条评论(评论表中的行)的推荐数量.

所以我认为代码应该像这样粗略的大纲.

    $username = 'bob';
$validrefferalcount = 0;
function validreferrals($username){

    $referreduser = SQL select * from users where referral='$username';

    foreach ($referreduser)   {

    $numberofcomments = SQL count * from comments where comment_username ='$referreduser';
if ($numberofcomments >= 10){
$validreferralcount = $validreferralcount + 1;
}

    }
return $validreferralcount;
    }

我为错误的语法等道歉...

谢谢阅读.

Answer 1

这个查询怎么样:

SELECT COUNT(*) FROM (
    SELECT username, COUNT(*) AS c_comments
    FROM users
        JOIN comments ON username = comment_username
    WHERE referral = 'referral'
    GROUP BY username
) t
WHERE t.c_comments > 10;