例如:
SELECT COUNT(a.id) FROM a WHERE a.fid=1;
SELECT COUNT(b.id) FROM b WHERE b.fid=1;这样可以得出两个结果,分别是10、1。如何将这两句sql合成一句来查询?我试过
SELECT COUNT(a.id),COUNT(b.id) FROM a INNER JOIN b ON a.fid=b.fid WHERE a.fid=1;
但是不行,怎样才能得出和上面分别查询一样的结果?
SELECT COUNT(a.id) FROM a WHERE a.fid=1;
SELECT COUNT(b.id) FROM b WHERE b.fid=1;这样可以得出两个结果,分别是10、1。如何将这两句sql合成一句来查询?我试过
SELECT COUNT(a.id),COUNT(b.id) FROM a INNER JOIN b ON a.fid=b.fid WHERE a.fid=1;
但是不行,怎样才能得出和上面分别查询一样的结果?
SELECT COUNT(a.id) FROM a WHERE a.fid=1), (
SELECT COUNT(b.id) FROM b WHERE b.fid=1)
(SELECT COUNT(b.id) FROM b WHERE b.fid=1) bid
select a.num,b.num from
(select fid,num=COUNT(id) from tba group by fid) a
join
(select fid,num=count(id) from tbb group by fid) b
on (a.fid=b.fid)