DefaultIfEmpty()的问题 急！！！！！！！！！！！！！

[zhaoyi19851214]

var yy = (from u in dbEntities.user_table
join f in dbEntities.foodp on u.foodId equals f.foodId into uf
from so in uf.DefaultIfEmpty()
select new{
u.id,
sa=(so==null?null:so)
}).ToList();

执行报错：LINQ to Entities 不识别方法“System.Collections.Generic.IEnumerable`1[MvcApplication1.Models.foodp] DefaultIfEmpty[foodp](System.Collections.Generic.IEnumerable`1[MvcApplication1.Models.foodp])”，因此该方法无法转换为存储表达式。

[zhaoyi19851214]

补充：sql 语句是select * from user_table u left join foodp f on u.foodId=f.foodId

[幸运的意外]

var yy = (from u in dbEntities.user_table
join f in dbEntities.foodp on u.foodId equals f.foodId into uf
where uf.DefaultIfEmpty()
select new{
u.id,
sa=(uf==null?null:uf)
}).ToList();
用这个代码试试看呢？

[yezie]

foodp里是不是有属性不能null的

DefaultIfEmpty(new foodp{...})自定一个empty的foodp试试

[zkcq2004]

Linq to Entity是不支持那个DefaultIfEmpty
可以这样写
(from u in dbEntities.user_table select u).Jion(dbEntities.foodp,a=>a.foodID,b=>b.foodID,(a,b)=>new{u.id,b=(b==null?null:b)}).ToList()

[「已注销」]

LINQ to Entities 不支持 DefaultIfEmpty

[ashou706]

var yy = (from u in dbEntities.user_table
join f in dbEntities.foodp on u.foodId equals f.foodId into uf
from so in uf.DefaultIfEmpty()
select new{
u.id,
sa=(so==null?null:so.?????????)
}).ToList();


问号的地方应当是字段名字吧