select b.prodname as "商品名称", c.etname as "厂名", a."价格" as "价格" from report a, prod b, et c where a.prodid = b.prodid (+) and a.etid = c.etid (+) and a.prodid = '某商品' and a.etid = '某厂' and a.date between <某时间段begin> and <某时间段end> ;This SQL can be performed only when the field "prodid" of "prod" table and the field "etid" of "et" table are primary keys!!
from report a, prod b, et c
where a.prodid = b.prodid (+)
and a.etid = c.etid (+)
and a.prodid = '某商品'
and a.etid = '某厂'
and a.date between <某时间段begin> and <某时间段end>
;This SQL can be performed only when the field "prodid" of "prod" table and the field "etid" of "et" table are primary keys!!