PHP唯一/区别于逗号分隔值的值 - php unique/distinct value from comma seperated value

php unique/distinct value from comma seperated value

本文关键字：分隔唯一区别于 PHP | 更新日期: 2023-09-26

我有一个带有tag_filter字段的wallposts MySql表，该字段将有一个逗号分隔的值。

我想从这个tag_filter字段中获取用户的所有唯一/不同标记，并填充在ul元素中。

每个用户可以有多个帖子。

如

post1: tag_filter = a, b, cPost2: tag_filter = a, d, ePost3: tag_filter = c, d, e

期望的输出将是

<ul>
<li>a</li>
<li>b</li>
<li>c</li>
<li>d</li>
</ul>

下面是目前为止的代码:

$tag_filter_list = mysql_query('SELECT tag_filter from wallposts where userid = '.$USER->id);
$list = "<ul>";
while ($tag_filter = mysql_fetch_array($tag_filter_list)) {
$value = $tag_filter["tag_filter"];
$info = explode(",", $value);
foreach( $info as $item ) {
$list.="<li>$item</li>'n";
}
}
$list .= "</ul>";
echo $list;

我还想用从上面获得的不同/唯一列表填充一个js var。

        var sampleTags = [
         <?php
                    $tag_filter_list = mysql_query('SELECT tag_filter from wallposts where userid = '.$USER->id);
                        $all_tags = array();
                        while ($tag_filter = mysql_fetch_array($tag_filter_list)) {
                          $value = $tag_filter["tag_filter"];
                          $info = explode(",", $value);
                          $all_tags = array_merge($all_tags, $info);
                        }
                        $tags = array_unique($all_tags); // values will be sorted by the function
                        foreach( $tags as $item ) {
                          $list = "$item";
                        }
                    echo join(',', $list);  
         ?>
        ];

这可能有帮助。

$tag_filter_list = mysql_query('SELECT tag_filter from wallposts where userid = '.$USER->id);
$tags = array();
while ($tag_filter = mysql_fetch_array($tag_filter_list)) {
    $value = $tag_filter["tag_filter"];
    $tags[] = explode(",", $value); // put all in an array
}
// now, join and remove duplicates and sort in ascending order
$tags = implode( ',', $tags );
$tags = explode( ',', $tags );
$tags = array_values( array_unique( $tags ) );
sort($tags);
$list = "<ul>";
foreach( $tags as $item ) {
    $list .= "<li>$item</li>'n";
}
$list .= "</ul>";
echo $list;

MySQL字段中逗号分隔的值是一个糟糕的数据库设计的标志，如果可能的话应该使用链接表

但是，在您的情况下，以下代码可能有效:

$all_tags = array();
while ($tag_filter = mysql_fetch_array($tag_filter_list)) {
  $value = $tag_filter["tag_filter"];
  $info = explode(",", $value);
  $all_tags = array_merge($all_tags, $info);
}
$tags = array_unique($all_tags); // values will be sorted by the function
foreach( $tags as $item ) {
  $list .= "<li>$item</li>'n";
}

把所有的标签放到一个javascript变量中:

<script type="text/javascript">
var sampleTags = [<?php echo explode(', ', $tags); ?>];
</script>

尝试用array_merge()合并所有tag_filter数组，然后使用array_unique()删除重复项

试试下面的例子:

<?php
$post_array = array('a,b,c','a,d,e','c,d,e');
$tag_list   = '<ul>';
$i=0;
while($i < count($post_array)){
$filter_explode = explode(',',$post_array[$i]);
$filter_count   = count($filter_explode);
for($j=0;$j<$filter_count;$j++)
{
if(!in_array($filter_explode[$j],$tag_list_build)){
$tag_list_build[] = $filter_explode[$j];
}
}
$i++;
}
$tag_list_build_count = count($tag_list_build);
for($k=0;$k<$tag_list_build_count;$k++)
{
$tag_list.= '<li>'.$tag_list_build[$k].'</li>';
}
$tag_list.= '</ul>';
echo $tag_list;
?>

我想这也许能帮助你解决你的问题。