Question

我有这个mssql查询，我想转换为linq

select * from personas
left join PersonaDocumento on PersonaDocumento.PersonaId=personas.Id
where personas.FirstName='23895389' or PersonaDocumento.Documento='23895389'

这不起作用：

from p in db.personas
join d in db.PersonaDocumento on p.Id equals d.PersonaId into dj1
where p.FirstName=='23895389' || dj1.Documento=='23895389'
from d in dj1.DefaultIfEmpty()
select p

Answer 1

我认为你在那里犯了三个错误：

from p in db.personas
join d in db.PersonaDocumento on p.Id equals d.PersonaId into dj1
where p.FirstName=='Jzuan' 
from d in dj1.DefaultIfEmpty()
where d.Documento=='23895389' 
select d

首先是join d on，正确的语法是in。第二，你是从p中选择而不是从你加入的表d中选择的。加dj1是一个元素列表，所以如果你需要过滤元素，你应该在之后进行。具体来自d dj1条款中的{{1}}

Answer 2

试试这个：

from p in db.personas
join d in db.PersonaDocumento on p.Id equals d.PersonaId into dj1
from ld in dj1.DefaultIfEmpty()
where p.FirstName=='Jzuan' || (ld != null && ld.Documento=='23895389')
select p

注意我如何重新排序条款。

Linq加入where子句不起作用

2 个答案: