sqlÓï¾ä ²éѯ - ÆäËûÊý¾Ý¿â¿ª·¢ / MySQL/Postgresql

SQL code:

select count(subid) as subnum,st.id,t.title,t.content from subtopics st JOIN topics t ON st.id=t.id
where st.id in (select id from topics where viewid='1')
group by st.id


ÎÒµÄÁ´½ÓÌõ¼þ Ϊt.id=st.id µ«t.id¶ÔÓ¦µÄst.idÓпÉÄÜûûÓÐ µ«ÎÒÏëÏÔʾt ±í µÄÄÚÈÝ SQLÓï¾äÔõôд  

---

select count(subid) as subnum,t.* from subtopics st right outer JOIN topics t ON t.id=st.id
where t.id in (select id from topics where viewid='1')
group by t.id
order by date desc

ÎÒÒ²ÊÔ³öÀ´ÁË »¹ÊÇлл´ó¼Ò O(¡É_¡É)O~