EXCEPT 是SQL SERVER 用法ORACLE 用 MINUS
select distinct maker
from product
where type = 'laptop'
MINUS
select distinct maker
from product
where type = 'pc' or type = 'printer';
select distinct maker
from product
where type = 'laptop'
MINUS
select distinct maker
from product
where type = 'pc' or type = 'printer';
解决方案 »
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