我正在开发一个post系统
因此，我必须显示用户的朋友和用户参与的群组的帖子
这是我显示帖子的代码。。
<?php
$sql = "SELECT * FROM posts WHERE uploader_id=:friend_id ORDER BY id DESC";
$query = $db->prepare($sql);
$query->execute(array(
":friend_id" => $friend_id
));
$rows = $query->fetchAll(PDO::FETCH_ASSOC);
foreach ($rows as $row) {
$name = $row['name'];
echo "POST BY $name";
}
$sql = "SELECT * FROM group_posts WHERE id=:member_group ORDER BY id DESC";
$query = $db->prepare($sql);
$query->execute(array(
":member_group" => $group_id
));
$rows = $query->fetchAll(PDO::FETCH_ASSOC);
foreach ($rows as $row) {
$name = $row['name'];
echo "POST BY $name";
}
?>
现在，我希望所有这些帖子都被打乱，这样post表和group_posts表的所有帖子都会按降序显示。
更新
我将代码编辑为
我发现，在编码我的邮政系统之前，首先我必须对其进行编码。。
<?php
$sql = "SELECT * FROM friends WHERE user_one=:me OR user_two=:me2 UNION SELECT * FROM group_members WHERE member_id=:me3";
$query = $db->prepare($sql);
$query->execute(array(
":me" => $my_id,
":me2" => $my_id,
":me3" => $my_id
));
$rows = $query->fetchAll(PDO::FETCH_ASSOC);
foreach ($rows as $row) {
$user_one = $row['user_one'];
$user_two = $row['user_two'];
$group_id = $row['group_id'];
if ($user_one == $my_id) {
$friend_id = $user_two;
} else {
$friend_id = $user_one;
}
echo $friend_id . "<BR>" . $group_id;
}
?>
现在，问题来了。。这成功地打印了$friend_id，但在打印$group_id时，它显示了一个未定义的索引"group_id"
我已检查所有字段是否正确。
尝试仅使用一个带有UNION 的查询
SELECT *
FROM (
SELECT name, id FROM posts WHERE uploader_id=:friend_id
UNION
SELECT name, id FROM group_posts WHERE id=:member_group
) p
ORDER BY p.id DESC
请注意，内部查询必须以相同的顺序返回相同的列数（我认为也是使用相同的名称/别名）。