嘿，这是我的问题，我正在使用 SQL 查询尝试根据帖子的元数据返回结果。此元数据由用户在用户界面内的帖子创建期间输入。我的过滤器有问题，它一次只对一个变量有效，但仅此而已(例如:如果选择了主题，它工作正常，但是如果选择了主题和媒体，它将不返回任何结果)这里是代码:

$db_build_post_filter_WHERE = array();
// Default to avoid errors on WHERE GROUP BY
$db_build_post_filter_WHERE [] = 'cmsp_post.post_id > 0';
//$db_build_post_filter_WHERE [] = 'cmsp_post.post_id = cmsp_post_meta.post_id';
if ( isset( $gnocore_cmsp_build_topic_slug_id_array[$filter_topic] ) ) {
    $db_build_post_filter_WHERE [] = 'post_meta_key = "topic_id" AND post_meta_value = ' . $gnocore_cmsp_build_topic_slug_id_array[$filter_topic];
}
if ( isset( $gnocore_cmsp_build_media_slug_id_array[$filter_media] ) ) {
$db_build_post_filter_WHERE [] = 'post_meta_key = "media_id" AND post_meta_value = ' . $gnocore_cmsp_build_media_slug_id_array[$filter_media];
}
if ( isset( $gnocore_cmsp_build_author_slug_id_array[$filter_author] ) ) {
$db_build_post_filter_WHERE [] = 'post_meta_key = "author_id" AND post_meta_value = ' . $gnocore_cmsp_build_author_slug_id_array[$filter_author];
}   

// PROJECT FILTER ARRAY 
$build_post_filter_array = array();
gnoshare_db_select ('cmsp_post LEFT JOIN cmsp_post_meta ON cmsp_post.post_id = cmsp_post_meta.post_id','cmsp_post.post_id',implode(' AND ',$db_build_post_filter_WHERE) . ' GROUP BY cmsp_post.post_id','cmsp_post.project_id, post_name, cmsp_post.post_id','db_build_post_filter_array_num','db_build_post_filter_array_results');
if ( $db_build_post_filter_array_num > 0 ) {
    foreach ($db_build_post_filter_array_results as $db_build_post_filter_array_result) {
        $build_post_filter_array [$db_build_post_filter_array_result->post_id] = '';
    }
}

我相信我的问题出在“PROJECT FILTER ARRAY”部分，如果有人可以提供帮助，我们将不胜感激。

干杯

编辑:将“AND”更改为“OR”会生成简单显示所有帖子的结果，我认为可以公平地说我的问题在于这行代码，但我仍然可以找不到生成我正在寻找的结果的方法。

gnoshare_db_select ('cmsp_post LEFT JOIN cmsp_post_meta ON cmsp_post.post_id = cmsp_post_meta.post_id','cmsp_post.post_id',implode(' OR ',$db_build_post_filter_WHERE) . ' GROUP BY cmsp_post.post_id','cmsp_post.project_id, post_name, cmsp_post.post_id','db_build_post_filter_array_num','db_build_post_filter_array_results');

编辑:这是我的表格(大致):

+----------+---------------+-----------------+  
| post_id  | post_meta_key | post_meta_value |  
+----------+---------------+-----------------+  
|     1    |   topic_id    |        1        |  
+----------+---------------+-----------------+  
|     1    |   media_id    |        1        |  
+----------+---------------+-----------------+  
|     1    |   author_id   |        2        |  
+----------+---------------+-----------------+  
|     2    |   media_id    |        2        |  
+----------+---------------+-----------------+  
|     2    |   topic_id    |        2        |  
+----------+---------------+-----------------+  

我希望它根据用户为帖子所做的选择进行过滤(例如:用户为帖子 1 选择主题 1、媒体 1 和作者 2，为帖子 2 选择媒体 2 和主题 2 显示在上面的表格)假设这个例子是正确的，如果过滤器选择了以下任何一项，我希望我的网页生成帖子一:按主题 1 过滤将仅显示帖子一，按主题 1 和媒体 1 过滤将仅显示帖子 1，按主题 1 过滤媒体 2 将显示一条消息，说明没有与所选条件匹配的消息，依此类推。这更清楚一点了吗？

最佳答案

如果我没记错的话，你应该在过滤器之间使用 OR 并用 () 将它们括起来。像这样的东西:

 $db_build_post_filter_WHERE [] = '(cmsp_post.post_id > 0)';
 if ( isset( $gnocore_cmsp_build_topic_slug_id_array[$filter_topic] ) ) {
   $db_build_post_filter_WHERE [] = '(post_meta_key = "topic_id" 
                                     AND post_meta_value = ' . 
                $gnocore_cmsp_build_topic_slug_id_array[$filter_topic].')';
 }
 if ( isset( $gnocore_cmsp_build_media_slug_id_array[$filter_media] ) ) {
   $db_build_post_filter_WHERE [] = '(post_meta_key = "media_id" 
                                    AND post_meta_value = ' . 
               $gnocore_cmsp_build_media_slug_id_array[$filter_media].')';
 }
 //Other conditions

// PROJECT FILTER ARRAY 
$build_post_filter_array = array();
gnoare_db_select ('cmsp_post 
                   LEFT JOIN cmsp_post_meta
                          ON cmsp_post.post_id = cmsp_post_meta.post_id',
                 'cmsp_post_post.post_id',
                 implode(' OR ',$db_build_post_filter_WHERE) . 
                ' GROUP BY cmsp_post.post_id','cmsp_post.project_id, post_name, cmsp_post.post_id','db_build_post_filter_array_num','db_build_post_filter_array_results');

关于php - 使用 MySQL 和 PHP 创建过滤函数，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/14823928/