PHP MySQL选择随机行 [英] PHP MySQL select random rows

问题描述

我在选择6个随机朋友时遇到问题

I have a problem selecting 6 random friends

这是我到目前为止得到的查询:

This is the query I've got so far:

$result = num_rows("SELECT * FROM friends WHERE member_id = '".$_SESSION['userid']."'");
if($result >= 6) {
    $f_num = 6;
} else {
    $f_num = $result;
}
for($i = 1; $i <= $f_num; $i++) {
    $q_get_member_friends = mysql_query("SELECT * FROM friends WHERE member_id = '".$_SESSION['userid']."' ORDER BY rand() LIMIT 1");
    $r_get_member_friends = mysql_fetch_array($q_get_member_friends);
    echo $r_get_member_friends['friend_with'];
}

如果登录的用户有6个以上朋友，我想随机选择6个朋友

I want to select 6 random friends if the logged in user has more or equal to 6 friends

现在坚持了一段时间:/

Stuck on this for a while now :/

感谢您的帮助:)

推荐答案

如果使用:

  SELECT * 
    FROM friends 
   WHERE member_id = '".$_SESSION['userid']."' 
ORDER BY rand() 
   LIMIT 6

如果该人只有3个朋友，查询将仅显示这三个朋友-这并不意味着查询将始终返回六行.

If the person only has 3 friends, the query will only show those three - it doesn't mean that the query will always return six rows.

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