LINQ 联表查询 取count 值
linq to sql 实现左外部连接:
var query=from a in A
join b in B
on a.ID equals b.aID into ab
from a1 in ab.DefaultIfEmpty()
select a1;
然后取query.Count()就行了
因为是延迟查询所以不会多查数据
linq to sql 实现左外部连接:
var query=from a in A
join b in B
on a.ID equals b.aID into ab
from a1 in ab.DefaultIfEmpty()
select a1;
然后取query.Count()就行了
因为是延迟查询所以不会多查数据