mysql一条sql完成统计帖子下面有多少条回复

mysql一条sql完成统计帖子下面有多少条回复

SELECT a.*,(select count(*) from theme as b where b.parent_id=a.id) as tiezi_count FROM `theme` as a WHERE a.id>0 

在需要取的字段中，写mysql的子查询进行统计。