レコードがnullの場合、SQLではどのように0を表示しますか?
select sales_id, totalbuy, totalsell, totalbuy + totalsell as total from
(select sales_id, SUM(CASE WHEN side= 'buy' THEN 1 ELSE 0 END) AS totalbuy,
SUM(CASE WHEN side= 'sell' THEN 1 ELSE 0 END) AS totalsell
from car_orders
where sales_id in ('sales1', 'sales2', 'sales3', 'sales4')only
GROUP BY sales_id)q
order by total desc
limit 0, 10;
car_orders
insert*(car_orders+ISNULL(car_orders,0)) を試した後、エラーが発生しました。