Linq：加入多種條件

Question

我想加入多個條件。問題在於它是「等於」和「不等於」的混合。這個previous answer只適用於如果你想加入'等於'。

from p1 in context.Set<PersonList>() 
join p2 in context.Set<PersonList>() 
on p1.Email equals p2.Email && p1.PersonID != p2.PersonID 

Answer 1

只需使用where捕捉額外條件：

from p1 in context.Set<PersonList>() 
join p2 in context.Set<PersonList>() 
on p1.Email equals p2.Email into p2j 
from p2 in p2j.DefaultIfEmpty() 
where p2 != null && p1.PersonID != p2.PersonID