Question

我有以下数据，员工栏目视为父项，每位员工都有子项发票，每张发票都有发票详细信息作为子项。我已将此数据绑定到类列表中。现在我想使用LINQ

从这个列表中创建层次结构列表

parent---> child--->subchild
Employee-Invoice--->InvoiceDetails

 List Data:

  Employee invoice InvoiceDetails    jan feb Mar Apr
  E1        I1        ID1             1   2  10  5
  E1        I1        ID2             1   3  11  6
  E1        I1        ID3             1   4  12  7
  E1        I2        ID1             1   5  13  8
  E1        I2        ID2             1   6  14  9
  E1        I2        ID3             1   7  15  10
  E2        I1        ID1             1   8  16  11
  E2        I1        ID2             1  10  17  12

Output : 

 E1
    --I1
        --ID1 1   2  10   5
        --ID2 1   3  11   6
        --ID3 1   4  12   7
    -I2
        --ID1 1   5  13   8
        --ID2 1   6  14   9
        --ID3 1   7  15   10
 E2
    --I1
       --ID1  1   8  16   11
       --ID2  1   10  17  12

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Answer 1

    var dataTree = employeeInvoiceDetails.GroupBy(__item => __item.Employee, __item => __item, (__key, __items) => new { Employee = __key, Invoices = __items.GroupBy(___item => ___item.invoice) });

    foreach (var employe in dataTree)
    {
        Console.WriteLine("--{0}", employe.Employee);
        foreach (var invoice in employe.Invoices)
        {
            Console.WriteLine("\t--{0}", invoice.Key);
            foreach (var employeeInvoiceDetail in invoice)
                Console.WriteLine("\t\t--{0} {1} {2} {3} {4}", employeeInvoiceDetail.InvoiceDetails, employeeInvoiceDetail.jan, employeeInvoiceDetail.feb, employeeInvoiceDetail.Mar, employeeInvoiceDetail.Apr);
        }
    }

Answer 2

我认为你的课程看起来像这样：

public class Employee
{
    public string Id;
    public List<Invoice> Invoices;
}

public class Invoice
{
    public string Id;
    public List<InvoiceDetails> InvoiceDetails;
}

public class InvoiceDetails
{
    public string Id;
}

我认为您的源数据是这样的：

var source = new []
{
    new { Employee = "E1", Invoice = "I1", InvoiceDetails = "ID1" },
    new { Employee = "E1", Invoice = "I1", InvoiceDetails = "ID2" },
    new { Employee = "E1", Invoice = "I1", InvoiceDetails = "ID3" },
    new { Employee = "E1", Invoice = "I2", InvoiceDetails = "ID1" },
    new { Employee = "E1", Invoice = "I2", InvoiceDetails = "ID2" },
    new { Employee = "E1", Invoice = "I2", InvoiceDetails = "ID3" },
    new { Employee = "E2", Invoice = "I1", InvoiceDetails = "ID1" },
    new { Employee = "E2", Invoice = "I1", InvoiceDetails = "ID2" },
};

然后这是您需要的查询：

var employees =
(
    from x in source
    group x by x.Employee into gxs
    select new Employee()
    {
        Id = gxs.Key,
        Invoices =
        (
            from y in gxs
            group y by y.Invoice into gys
            select new Invoice()
            {
                Id = gys.Key,
                InvoiceDetails =
                (
                    from z in gys
                    select new InvoiceDetails()
                    {
                        Id = z.InvoiceDetails,
                    }
                ).ToList()
            }
        ).ToList()
    }
).ToList();

这给了我这个结果：

如何使用LINQ

2 个答案: