Question

我想从我的SQL服务器数据库中选择数据，其中6个表通过外键连接在一起。为了根据表4中的参数从某些列中选择数据，而其他列位于其他表中。表格中的关系和我的代码如下。表1与表2，表3，表4，表5有关表2与表3，表4有关。此代码不适用于产品或其他表。它只是用于人，而我想根据产品的名称进行选择。

select
    Person.Name,
    Person.Last_Name,
    Call.Email,
    Call.Email_t,
    Call.Mobile,
    Call.mobile_two,
    Call.Website,
    Person.expert_one, 
    Person.expert_one, 
    Organization.Name,
    Product.Product_Name,
    Patent.Pat_Name   

from Person
inner join Call on Person.Call_Id = Call.ID
right join Organization on Person.Organize_ID = Organization.ID
left join Product on Product.Person_Id_o = Person.ID and Product.Person_Id_t = Person.ID
left join Patent on Patent.Person_Id_o = Person.ID and Patent.person_two = Person.ID and Patent.person_three = Person.ID  and patent.Person_four = Person.ID
right join Education on Education.Person_ID = Person.ID
where Product.Product_Name LIKE N'%name%'

Answer 1

因此，您可以更改连接并使用Product表作为基表。

例如：

...
from Product 
left join Person on (Person.ID = Product.Person_Id_o and Person.ID = Product.Person_Id_t)
left join Call on Call.ID = Person.Call_Id
left join Organization Org on Org.ID = Person.Organize_ID
left join Patent on (Patent.Person_Id_o = Person.ID and Patent.person_two = Person.ID and Patent.person_three = Person.ID and patent.Person_four = Person.ID)
left join Education on Education.Person_ID = Person.ID
where Product.Product_Name LIKE N'%name%'

根据您想要限制的方式，其中一些左连接可以更改为内连接。

但说实话，我发现加入专利有点奇怪所有这4个人的身份真的需要是同一个身份证吗？

在SQL Server

1 个答案: