MySQL连接查询计数为每个结果返回一行答案

【问题标题】：MySQL joined query count returning a row for each resultMySQL连接查询计数为每个结果返回一行
【发布时间】：2012-07-17 13:08:54
【问题描述】：

所以，我正在执行一个自定义 wordpress 查询来拉取事件（事件存储在自定义字段（元数据）中，因此需要 JOIN）并且我想获得返回的行数。我的问题是我收到一堆返回的行，每行都包含针对返回的每个帖子 ID 的计数。

我的查询有点像这样：

SELECT count(*)
FROM   wp_posts AS wposts 
   LEFT JOIN wp_postmeta AS metafeatured 
          ON wposts.id = metafeatured.post_id 
   LEFT JOIN wp_postmeta AS metastart 
          ON wposts.id = metastart.post_id 
   LEFT JOIN wp_postmeta AS metaend 
          ON wposts.id = metaend.post_id 
   LEFT JOIN wp_term_relationships 
          ON ( wposts.id = wp_term_relationships.object_id ) 
   LEFT JOIN wp_term_taxonomy 
          ON ( wp_term_relationships.term_taxonomy_id = 
               wp_term_taxonomy.term_taxonomy_id ) 
WHERE  wposts.post_type = 'll_events' 
   AND wposts.post_status = 'publish' 
   AND ( ( ( metastart.meta_key = 'll_events_startdate' 
             AND Cast(metastart.meta_value AS UNSIGNED) < 1342997940 ) 
           AND ( metaend.meta_key = 'll_events_enddate' 
                 AND Cast(metaend.meta_value AS UNSIGNED) > 1342525664 ) ) 
          OR ( ( metastart.meta_key = 'll_events_startdate' 
                 AND Cast(metastart.meta_value AS UNSIGNED) <= 1342997940 ) 
               AND ( metaend.meta_key = 'll_events_enddate' 
                     AND Cast(metaend.meta_value AS UNSIGNED) >= 1342525664 
                   ) ) 
          OR ( ( metastart.meta_key = 'll_events_startdate' 
                 AND Cast(metastart.meta_value AS UNSIGNED) BETWEEN 
                     1342525664 AND 1342997940 
                   ) 
               AND ( metastart.meta_key = 'll_events_enddate' 
                     AND Cast(metaend.meta_value AS UNSIGNED) BETWEEN 
                         1342525664 AND 1342997940 
                   ) ) 
          OR ( ( metastart.meta_key = 'll_events_startdate' 
                 AND Cast(metastart.meta_value AS UNSIGNED) BETWEEN 
                     1342525664 AND 1342997940 
                   ) 
               AND ( metaend.meta_key = 'll_events_enddate' 
                     AND Cast(metaend.meta_value AS UNSIGNED) <= 1 ) ) ) 
GROUP BY wposts.ID, metastart.post_id, metaend.post_id, wp_term_relationships.object_id
ORDER BY metastart.meta_value ASC

我尝试了组、计数等的大量组合，但无法获得预期结果（结果集中的单行包含“计数”）。相反，我的结果集看起来像：

count(*)
24
30
30
30
12
16
1

...等等，我需要的地方：

count(*)
139

【问题讨论】：

标签： mysql sql wordpress group-by left-join

【解决方案1】：

只需删除 GROUP BY 子句

【讨论】：