內部聯接查詢幫助

Question

我有兩個疑問

$query1="SELECT staffid, COUNT(staffid) FROM enrll GROUP BY staffid ORDER BY COUNT(staffid) DESC";
$query2="SELECT staffid FROM staff as s WHERE auth = '1' AND NOT EXISTS ( SELECT staffid from shdl as h where s.staffid=h.staffid and h.shdldt='".$unixdt."')";

這兩個查詢都返回數組中的值，我想從query1中找出那些具有與query2的內部連接的人員，而值將在數組中。

注意兩個查詢的組合查詢將返回最終查詢。

Answer 1

select e.staffid, count(e.staffid)
from enrll e
join staff s on e.staffid=s.staffid
where s.auth = '1' and NOT EXISTS ( 
    SELECT staffid from shdl as h 
    where s.staffid=h.staffid and h.shdldt='$unixdt')
group by e.staffid
ORDER BY COUNT(staffid) DESC