加一个别名有2结果??求9

[肥胖的柠檬]

select orderbase.customer,year(orderbase.deliverydate) yy, month(orderbase.deliverydate) mm
from deliverys
inner join orderbase on deliverys.orderno=orderbase.orderno
inner join delivery on delivery.cid=deliverys.pcid
inner join currency on orderbase.currency=currency.currency
WHERE Delivery.customer like'Osram'
and Delivery.Deliverydate >= '2006-12-01 00:00:00'

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select a.customer,year(a.deliverydate) yy, month(a.deliverydate) mm
from deliverys b
inner join orderbase a on b.orderno=a.orderno
inner join delivery d on d.cid=b.pcid
inner join currency e on a.currency=e.currency
where a.customer = 'Osram'
and a.deliverydate >= '2006-12-01 00:00:00'


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远行结果:

（所影响的行数为 28 行）


（所影响的行数为 35 行）

??为什么,我只不过给了一个别名

[leo_lesley]

select a.customer,year(a.deliverydate) yy, month(a.deliverydate) mm
from deliverys b
inner join orderbase a on b.orderno=a.orderno
inner join delivery d on d.cid=b.pcid
inner join currency e on a.currency=e.currency
where d.customer = 'Osram' ---- 这个地方应该是 d 而不是 a
and d.deliverydate >= '2006-12-01 00:00:00' ---- 这个地方应该是 d 而不是 a