什么样的人会写这样的sql语句(实际工程中)
select fir.name as topcataname,
sec.name as seccataname,
thd.name as thdcataname,
p.title,
up.hasproduct,
up.price,
up.inputdate
from userproduct up
inner join product p on up.productid=p.productid
inner join cata thd on p.catano=thd.catano
inner join cata sec on thd.upcatano= sec.catano
inner join cata fir on sec.upcatano= fir.catano ";