从查询中获取X最热门的标签

Question

$query = "SELECT tag.name, tag.id 
     FROM #__k2_tags as tag 
     LEFT JOIN #__k2_tags_xref AS xref ON xref.tagID = tag.id 
     WHERE xref.itemID IN (".implode(',', $IDs).") 
     AND tag.published = 1"; 

在xref.tagID

是标签ID如：标签识别：42是100倍，标签识别：15为90倍，标签识别：56的10倍，我想先展示，然后42 15然后56（我想cound多少标签是xref.tagID并序）

Answer 1

您可以group by功能尝试：

"SELECT tag.id, count(*) 
     FROM #__k2_tags as tag 
     LEFT JOIN #__k2_tags_xref AS xref ON xref.tagID = tag.id 
     WHERE xref.itemID IN (".implode(',', $IDs).") 
     AND tag.published = 1 
GROUP BY tag.id"; 

Answer 2

试试这个：

$query = " 
SELECT * 
FROM (
    SELECT tag.name, tag.id, count(xref.id) AS tagCount 
    FROM #__k2_tags as tag 
    LEFT JOIN #__k2_tags_xref AS xref ON xref.tagID = tag.id 
    WHERE xref.itemID IN (".implode(',', $IDs).") AND tag.published = 1 
    GROUP BY tag.name, tag.id 
) 
ORDER BY tagCount"; 

通过子查询中的GroupBy，您可以计算每种标签类型的标签出现量。
主要查询需要按聚合值tagCount进行排序。