这个sql该怎么写，急用

Question

我写了一段sql，数值不对，谁能帮忙看看哪地方错了

SELECT a.name,IfNULL(b.count,0) count from areac a left join (
    SELECT
        a.id,
        a.NAME,
        count(w.id) count
    FROM
        warn w,
        vehicle v,
        township t,
        areac a 
    WHERE
        w.device_no = v.device_no 
        AND v.prop_company_id = t.prop_company_id 
        AND t.area_id = a.id 
        AND v.be_deleted = 0 
        AND t.be_deleted = 0 
        GROUP BY
        a.id
) b on a.id=b.id
where a.pid=371600
ORDER BY count desc

Answer 1

你先说说你要查什么，不然看得好累
select t4.name,count(*) as count from
(select t4.id,t4.name,t4.pid from warn t1
left join
vehicle t2
on t1.device_no=t2.device_no
left join
township t3
on t2.prop_company_id=t3.prop_company_id
left join
areac t4
on t3.area_id=t4.id
where t2.be_deleted = 0 and t3.be_deleted = 0
) t
where t.pid=371600
group by t.id
order by count desc
;