mysql - 在三个表(mysql)上使用联合命令

Question

我有以下内容:

tblOwner: owner_num,lname,fname (PK owner_num)
tblMarina_slip: owner_num, slip_id (PK slip_id, FK owner_num)
tblService_Requests: service_id, slip_id, description (PK service_id, FK slip_id)

我是 MySql 的新手，需要使用联合命令来获取输出

tblOwner.Owner_num, tblOwner.Lname, tblOwner.Fname, tblServiceRequests.service_id, tblServiceRequests.Description

我不知道如何使用“联合”命令来获取所需的数据集，当这三个表之间的唯一连接是 tblMarina_slip 和 tblService_Requests 中的外键时。

Answer 1

你不需要联合命令:

select  tow.Owner_num, tow.Lname, tow.Fname, ts.service_id, ts.Description
  from  tblOwner tow, tblServiceRequests ts, tblMarina_slip tm
 where  tow.owner_num = tm.owner_num
   and  tm.slip_id    = ts.slip_id