把北风公司的订单替换,用提都没提就要求会的coalesce函数
select employeeid, firstname||' '||lastname,
case
when coalesce(shipregion,'') = '' then '姓名为空' else shipregion
end 区域
from orders
把北风公司的订单替换,用提都没提就要求会的coalesce函数
select employeeid, firstname||' '||lastname,
case
when coalesce(shipregion,'') = '' then '姓名为空' else shipregion
end 区域
from orders