Question

我必须将两种不同类型的数组连接起来以形成一个新数组。

让我们看看应该在其中创建条件的类。

public class MutualFundParameter
{
    public int Id { get; set; }
    public string AcNo { get; set; }
    public string CustomerName { get; set; }
}

public class VoucherDetails
{
    public int Id { get; set; }
    public int AcNo { get; set; }
    public decimal Amount { get; set; }
    public int MasterId { get; set; }
}

public class VoucherMaster
{
    public int Id { get; set; }
    public DateTime DateTime { get; set; }
    public ICollection<VoucherDetails> VoucherDetails { get; set; }
}

让我们将一些数据添加到该对象中

// mutual fund parameter
var mutualFundParameters = new List<MutualFundParameter>
{
    new MutualFundParameter { Id = 1, AcNo = "001", CustomerName = "Ram" },
    new MutualFundParameter { Id = 2, AcNo = "002", CustomerName = "Shyam" },
    new MutualFundParameter { Id = 3, AcNo = "003", CustomerName = "Hari" },
    new MutualFundParameter { Id = 4, AcNo = "004", CustomerName = "Gita" },
    new MutualFundParameter { Id = 5, AcNo = "005", CustomerName = "Sita" },
};

// voucher details
var voucherDetails = new List<VoucherDetails>
{
    new VoucherDetails { Id = 1, AcNo = 001, Amount = 10.00M, MasterId = 1 },
    new VoucherDetails { Id = 2, AcNo = 001, Amount = 120.00M, MasterId = 1 },
    new VoucherDetails { Id = 3, AcNo = 002, Amount = 20.00M, MasterId = 1 },
    new VoucherDetails { Id = 4, AcNo = 002, Amount = 120.00M, MasterId = 1 },
    new VoucherDetails { Id = 5, AcNo = 002, Amount = 30.00M, MasterId = 1 },
    new VoucherDetails { Id = 6, AcNo = 002, Amount = 20.00M, MasterId = 1 },
    new VoucherDetails { Id = 7, AcNo = 003, Amount = 20.00M, MasterId = 1 },
    new VoucherDetails { Id = 8, AcNo = 003, Amount = 20.00M, MasterId = 1 },
    new VoucherDetails { Id = 9, AcNo = 003, Amount = 20.00M, MasterId = 1 },
    new VoucherDetails { Id = 10, AcNo = 004, Amount = 10.00M, MasterId = 2 },
    new VoucherDetails { Id = 11, AcNo = 005, Amount = 20.00M, MasterId = 2 },
    new VoucherDetails { Id = 12, AcNo = 006, Amount = 30.00M, MasterId = 2 },
    new VoucherDetails { Id = 13, AcNo = 007, Amount = 40.00M, MasterId = 2 },
    new VoucherDetails { Id = 14, AcNo = 008, Amount = 50.00M, MasterId = 2 },
    new VoucherDetails { Id = 15, AcNo = 009, Amount = 60.00M, MasterId = 2 },
    new VoucherDetails { Id = 16, AcNo = 001, Amount = 70.00M, MasterId = 2 },
};

// voucher
var voucherMasters = new List<VoucherMaster>
{
    new VoucherMaster
    {
        Id = 1,
        VoucherDetails = voucherDetails
                           .Where(x => x.MasterId == 1)
                           .ToList(),
        DateTime = DateTime.Now }
};

现在我需要将MutualFundParameter与VoucherDetails一起加入，但这在“ Voucher Master”列表中要加入，我已经尝试过了，但这不能按预期工作

var res = voucherMasters.Join(
          mutualFundParameters,
          voucher => voucher.VoucherDetails.FirstOrDefault().AcNo,
          mutual => mutual.AcNo,
          (voucher, mutual) => new
          {

          }
);

感谢您的积极回应。

Answer 1

假设interFundParameter和voucherDetail中的AcNo是同一类型，这是查询内存中集合或db的两个示例：（注意：我尚未编译/运行代码，因此请原谅任何语法错误）

var resultFromInMemory = (
        from vd in voucherMasters.SelectMany(x => x.voucherDetails)
        join mfp in mutualFundParameters on mfp.AcNo equals vd.AcNo
        select new { vd, mfp });

var resultFromDb = (
        from vd in db.voucherDetails
        join mfp in db.mutualFundParameters on mfp.AcNo equals vd.AcNo
        select new { vd, mfp });

对于内存中集合，因为您希望voucherDetails是voucherMaster的子集合，所以在commonFundParameters和voucherDetails之间执行联接需要首先将voucherDetails合并到一个临时的单个集合中，SelectMany可以帮助

如果是数据库（假设是关系数据库），则不需要这种中间集合，因为每个实体都是其中的平面表。

LINQ-加入列表

1 个答案: