在linq查询中分配IEnumerable列表

Question

我遇到了关注linq查询的问题。

public class Address
    {
        public int addressID { get; set; }
        public string address { get; set; }
    }

public class AdvanceClient
    {
        public int ClientID { get; set; }
        public string Name { get; set; }
        public string Mobile { get; set; }

        public IEnumerable<Address> Addresses { get; set; } 

    }

在下面的linq查询中，我想将IEnumerable地址列表分配给Addresses属性。我在tblAdvanceClient和tblAddress表之间有一对多的关系。

IEnumerable<AdvanceClient> addcli = from tbcli in dc.tblAdvanceClients
                                                join tbadd in dc.tblAddresses
                                                on tbcli.AddressID equals tbadd.AddressID
                                                select new AdvanceClient
                                                {
                                                    ClientID = tbcli.ClientID,
                                                    Company = tbcli.Company,
                                                    Fax = tbcli.Fax,
                                                    Mobile = tbcli.Mobile,
                                                    Name = tbcli.Mobile,
                                                    Telephone = tbcli.Telephone,
                                                    Addresses = new Address { } // Here i need to get the list of address to each client
                                                };

Answer 1

而不是

Address = new Address { }

将其更改为

Address = tbcli.Addresses //Since you already have a property in AdvanceClient

所以你的查询是：

IEnumerable<AdvanceClient> addcli = 
        from tbcli in dc.tblAdvanceClients
        join tbadd in dc.tblAddresses
            on tbcli.AddressID equals tbadd.AddressID
            select new AdvanceClient
            {
                ClientID = tbcli.ClientID,
                Company = tbcli.Company,
                Fax = tbcli.Fax,
                Mobile = tbcli.Mobile,
                Name = tbcli.Mobile,
                Telephone = tbcli.Telephone,
                Address = tbcli.Addresses
            };

Answer 2

您是否正在使用EntityFramework来检索数据？如果是这样，那么你可以改变你的模型

 

public class Address
    {
        public int addressID { get; set; }
        public string address { get; set; }
    }

public class AdvanceClient
    {
        public int ClientID { get; set; }
        public string Name { get; set; }
        public string Mobile { get; set; }
        public int AddressId { get; set; }

        public virtual Address Addresses { get; set; } 

    }

 

EntityFramework将为您加载地址数据。

Answer 3

这个设计对我来说有点奇怪，有一个地址列表总是只包含一个项目，但如果你肯定需要这个，你可以查询以下内容：

    var addcli = from tbcli in dc.tblAdvanceClients
                join tbadd in dc.tblAddresses
                on tbcli.AddressID equals tbadd.AddressID into addrList
                select new AdvanceClient
                {
                    ClientID = tbcli.ClientID,
                    Company = tbcli.Company,
                    Fax = tbcli.Fax,
                    Mobile = tbcli.Mobile,
                    Name = tbcli.Mobile,
                    Telephone = tbcli.Telephone,
                    Addresses = from row in addrList
                                select new Address 
                                {
                                    addressID = row.AddressID, 
                                    address = row.Address 
                                }
                };

Answer 4

我很抱歉，如果我不理解，但我认为它应该如下，因为地址和客户表通过AddressID一对一关联

public class Address
{
    public int addressID { get; set; }
    public string address { get; set; }
}

public class AdvanceClient
{
    public int ClientID { get; set; }
    public string Name { get; set; }
    public string Mobile { get; set; }

    //It can has only one address
    public Address Address { get; set; } 

}

并查询：

IEnumerable<AdvanceClient> addcli = from tbcli in dc.tblAdvanceClients
                                    join tbadd in dc.tblAddresses
                                    on tbcli.AddressID equals tbadd.AddressID
                                    select new AdvanceClient
                                    {
                                        ClientID = tbcli.ClientID,
                                        Company = tbcli.Company,
                                        Fax = tbcli.Fax,
                                        Mobile = tbcli.Mobile,
                                        Name = tbcli.Mobile,
                                        Telephone = tbcli.Telephone,
                                        //tbadd is the address which you are looking for
                                        Addresses = tbadd;
                                    };