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±í:

Order Details

OrderID  (PK,PK,INT NOT NULL)
ProductID (PK,PK,INT NOT NULL)
UnitPrice (money,NOT NULL)
Quantity  (smallint ,NOT NULL)

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select OrderId, max(Quantity)
from OrderDetails
group by OrderId
union
select OrderId, min(Quantity)
from OrderDetails
group by OrderId

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SQL code:
select OrderId,Quantity
from tb t
where not exists(select 1 from tb where id>t.id)
or not exists(select 1 from tb where id<t.id

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ÒýÓÃ

SQL codeselect OrderId,Quantityfrom tb twherenotexists(select1from tbwhere id>t.id)ornotexists(select1from tbwhere id<t.id

ÐÞÕý

SQL code:
select OrderId,Quantity
from tb t
where not exists(select 1 from tb where Quantity>t.Quantity)
or not exists(select 1 from tb where Quantity<t.Quantity)

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SQL code:
select * from [Order Details] t