我有一个名为Customer的实体,它有三个属性:
public class Customer {
public virtual Guid CompanyId;
public virtual long Id;
public virtual string Name;
}
我还有一个名为Splitting的实体,它有三个属性:
public class Splitting {
public virtual long CustomerId;
public virtual long Id;
public virtual string Name;
}
现在我需要编写一个获取companyId和customerId的方法。该方法应返回与companyId中特定customerId相关的拆分列表。 像这样:
public IList<Splitting> get(Guid companyId, long customrId) {
var res=from s in Splitting
from c in Customer
...... how to continue?
return res.ToList();
}
答案 0 :(得分:79)
var res = from s in Splitting
join c in Customer on s.CustomerId equals c.Id
where c.Id == customrId
&& c.CompanyId == companyId
select s;
使用Extension methods
:
var res = Splitting.Join(Customer,
s => s.CustomerId,
c => c.Id,
(s, c) => new { s, c })
.Where(sc => sc.c.Id == userId && sc.c.CompanyId == companId)
.Select(sc => sc.s);
答案 1 :(得分:5)
你可以在visual studio中找到一大堆Linq示例。
只需选择Help -> Samples
,然后解压缩Linq样本。
打开linq示例解决方案并打开 SampleQueries 项目的 LinqSamples.cs 。
您正在寻找的答案是方法Linq14:
int[] numbersA = { 0, 2, 4, 5, 6, 8, 9 };
int[] numbersB = { 1, 3, 5, 7, 8 };
var pairs =
from a in numbersA
from b in numbersB
where a < b
select new {a, b};
答案 2 :(得分:2)
不是100%肯定这两个实体之间的关系,但这里是:
IList<Splitting> res = (from s in [data source]
where s.Customer.CompanyID == [companyID] &&
s.CustomerID == [customerID]
select s).ToList();
IList<Splitting> res = [data source].Splittings.Where(
x => x.Customer.CompanyID == [companyID] &&
x.CustomerID == [customerID]).ToList();
答案 3 :(得分:1)
public IList<Splitting> get(Guid companyId, long customrId) {
var res=from c in Customers_data_source
where c.CustomerId = customrId && c.CompanyID == companyId
from s in Splittings_data_srouce
where s.CustomerID = c.CustomerID
select s;
return res.ToList();
}