array_unique 在 PHP 中不起作用？
我的 MySql 数据库中有一个表：
pageid | text
-----------+----------
1 | test
-----------+----------
2 | example
-----------+----------
3 | another
-----------+----------
1 | example1
和这个 PHP 代码：
$query = "SELECT pageid FROM test";
$result = mysql_query($query);
while($row = mysql_fetch_array($result))
{
$id = $row['pageid'];
$id1 = array($id);
$id2 = array_unique($id1);
foreach ($id2 as $value)
{
echo $value . "<br>";
}
}
但它返回：
1
2
3
1
我想让 pageid 唯一。所以我想回显一次数字1。就像这样：
1
2
3
那么我做错了什么？我怎样才能实现我想要的目标？
预先感谢...
[我知道这段代码没有多大意义，但这只是这个问题的演示，我有一个更复杂的代码:)]
I have got a table in my MySql database:
pageid | text
-----------+----------
1 | test
-----------+----------
2 | example
-----------+----------
3 | another
-----------+----------
1 | example1
and this PHP code:
$query = "SELECT pageid FROM test";
$result = mysql_query($query);
while($row = mysql_fetch_array($result))
{
$id = $row['pageid'];
$id1 = array($id);
$id2 = array_unique($id1);
foreach ($id2 as $value)
{
echo $value . "<br>";
}
}
But it returns:
1
2
3
1
I would like to make the pageids unique. So I would like to echo out the number 1, once. Like this:
1
2
3
So what am I doing wrong? How could I achieve what I want?
Thanks in advance...
[I know that this code doesn't make much sense, but this is just a demo for this question and I have a much more complicated code :) ]
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当然，在这种情况下真正的答案是首先选择不同的记录：
但是至于为什么你的代码不起作用......
你将
$id1声明为数组，但不附加到它。相反，您每次只是创建一个 1 元素数组。相反，附加所有结果，然后调用 array_unique()Of course, the real answer in this situation is to select distinct records to begin with:
But as to why your code doesn't work...
You are declaring
$id1as an array, but not appending to it. Instead you're just creating a 1 element array each time. Instead, append all results then callarray_unique()您可以在
SELECT中执行以下操作：SELECT DISTINCT pageid FROM test或使用GROUP BY，如下所示：You could do it in your
SELECTby doing something likeSELECT DISTINCT pageid FROM testor by usingGROUP BYlike this:您可以在 sql 查询中使用 Distinct 关键字。这将返回 Page 的唯一值
You can use Distinct keyword in your sql query.That will return you the unique vaues of Page