SELECT ao.animal_id, ao.name
from animal_outs ao left outer join animal_ins ai
on ao.animal_id = ai.animal_id
where ai.datetime is null
order by ao.animal_id
SELECT ai.animal_id, ai.name
from animal_ins ai join animal_outs ao
on ai.animal_id = ao.animal_id
where ai.datetime > ao.datetime
order by ai.datetime
SELECT ai.name, ai.datetime
from animal_ins ai left outer join animal_outs ao
on ai.animal_id = ao.animal_id
where ao.datetime is null
order by ai.datetime
limit 3
SELECT p.product_code, sum(p.price*os.sales_amount) as SALES
from product p join offline_sale os
on p.product_id = os.product_id
group by p.product_code
order by SALES desc, p.product_code asc