Question

有人可以向我解释如何在此联接中关联这些名称吗？当我执行时，我得到错误，说明From子句中的对象具有相同的暴露名称

select
inv_mast.item_id as Item,
inv_loc.location_id as location,
company.company_name as company,
vendor_supplier.vendor_id as vendorID
from
inv_loc
join inv_mast on inv_mast.inv_mast_uid = inv_loc.inv_mast_uid 
join inv_loc on company.company_id = inv_loc.company_id 
JOIN company ON (company.company_id = vendor_supplier.company_id)

Answer 1

您加入inv_loc两次 - 您需要修复联接或引入别名，如下所示：

select      inv_mast.item_id as Item,
            mast.location_id as MasterLocation,
            companylocation.location_id as CompanyLocation,
            company.company_name as company,
            vendor_supplier.vendor_id as vendorID

from        inv_loc AS mast

join        inv_mast 
    on      inv_mast.inv_mast_uid = mast.inv_mast_uid 

join        inv_loc AS companylocation
    on      company.company_id = companylocation.company_id 

JOIN        company 
    ON      company.company_id = vendor_supplier.company_id

不了解sql连接上的相关名称

1 个答案: