好了。
假设$topic['is_new']由"7325823"组成，accID是63426，然后它更新为7325823|63426，但如果我再次重新加载页面，它会删除7325823|所以它只有63426。我不想那样。
什么错了吗?Can 't figure it out
$accID = userid goes here;
$topic['is_new'] = "72482|81249|8124|42534|...and so on"; // user ids that i get from field in topics table
$list_of_ids = explode('|', $topic['is_new']);
// lets see if the user has already been here
if (!in_array($accID, $list_of_ids)) {
$in = isset($topic['is_new']) && !in_array($accID, $list_of_ids) ? $topic['is_new'].'|'.$accID : $topic['is_new'].'|'.$accID;
} else {
// if he havent, add him to the list
$in = $accID;
}
// yes i know, PDO is better
mysqli_query("UPDATE topics
SET num_views = num_views+1, is_new = '$in'
WHERE id = $tid") or die(mysqli_error($link));
这就是我想实现的:自定义php论坛-显示新的/未读的帖子
您的"add him to the list"代码使用新的用户ID覆盖列表，而不是附加到列表中。此外，你的"查看用户是否已经在这里"的代码的形式是"if X then Y else Y"。
试试这样写:
$list_of_ids = $topic['is_new'] ? explode("|",$topic['is_new']) : array();
// above code ensures that we get an empty array instead of
// an array with "" when there are no IDS
if( !in_array($accID,$list_of_ids)) $list_of_ids[] = $accID;
$newIDstring = implode("|",$list_of_ids);
// do something with it.
也就是说，你这样做是一个非常糟糕的主意。但是，在不了解你的项目的情况下，我真的无法告诉你什么是好主意。
您的问题在您的if语句中:
// lets see if the user has already been here
if (!in_array($accID, $list_of_ids)) {
//if the user is not in the array, they are added here
//your if here was returnign the same thing either way, so simplify
$in = $topic['is_new'].'|'.$accID;
} else {
//HERE is your problem ...
//if the user is found in the array, you set $in to just the account id and update the database ...
//I would think you would not want to do anything here ...
//so comment out the next line
//$in = $accID;
}
这让我大吃一惊，也许这是有意为之。
$in = isset($topic['is_new']) && !in_array($accID, $list_of_ids) ? $topic['is_new'].'|'.$accID : $topic['is_new'].'|'.$accID;
结果是一样的:
? $topic['is_new'].'|'.$accID
: $topic['is_new'].'|'.$accID
这里的下一个(或主要)问题是，您的else需要工作。
考虑这个流程:
$topic['is_new'] = '7325823';
$list_of_ids would contain 7325823
!in_array() so it appends it
刷新页面:
$topic['is_new'] = '7325823|63426';
$list_of_ids would contain 7325823, 63326
in_array() === true so $in = $accID
主题更新为63426?