C# .NET Key to Object mapping where the key is a member of the object

C# .NET Key to Object mapping where the key is a member of the object


Hi experts,

I have the following objects which act to store a list of account values. Each Account has a unique AccountId(which has a contryId and numericId) and a collection of AccountValues(which is just a decimal value for any one of the AccountValue enumerations - see code snippet below).

I need to store a collection of Accounts that can be be efficiently indexed using the AccountId(perhaps as a string using the ToString() overload - see AccountId.ToString() in the code snippet ) as the key.

I had originally wrote my code to store the Accounts as a collection i.e. List<Account> and used the account.Find(compareAccountId) method with a compareAccountId predicate to find a specific Account however my list of account objects is quite large so I would really like to use a Hashtable collection, such as NameValueCOllection to increase the speed of access i.e. to index rather than find.

This would take the form:

NameValueCollection<string AccountId, Account> accountAtAccountId

I would use the AccountId.ToString() method to retrive a string representation of the AccountId for the collection Key.

However, I don't believe this to be a good design choice because I am storing the AccountId in two places: 1) as the Key part of the collection and 2) in the Account Object itself.

This is not ideal as we have dublicate data and a change in the Account.AccountId could lead to a senario where the accountAtAccountId key could read "USA123456" however the Account stored at this index could have a  Account.AccountId that after an update could read some completely different AccountId such as "UK3435432".

I don't want to move the AccountId out of the Account data type as this would leave the Account as an Account without an identifier.

Perhaps I could store some form of a reference to the AccountId as the Key in the NameValueCollection.
 
Appreciate any suggestions?

Thanks,
jStart Free Trial

1:
2:
3:
4:
5:
6:
7:
8:
9:
10:
11:
12:
13:
14:
15:
16:
17:
18:
19:
20:
21:
22:
23:
24:
25:
26:
27:
28:
29:
30:
31:
32:
33:
34:
35:
36:
37:
38:
39:
40:
41:
42:
43:
44:
45:
46:
47:
48:
49:
50:
51:
52:
53:

struct Account
{
  public AccountId accountId;
  public List<AccountValue> accountStatistics = new List<AccountValue>;
  
  public Account(AccountId accountId)
  {
    this.accountId = accountId;
    
  }
}
 
 
// We have an Account Id stored as a struct
struct AccountId
{
  public string countryId
  public int numericId
 
  public AccountId(string countryId, int numericId)
  {
     this.countryId = countryId;
     this.numbericId = numericId;
  } 
 
  // overload the the ToString() method to return a composite of the Id
  public override ToString()
  {
    return countryId + numericId.ToString();
  }
}
 
struct AccountValue
{
   public decimal value;
 
   //defalut to one year turnover  
   public AccountValueType type = AccountValueType.OneYearTurnover;
     
   public AccountValue(AccountValueType type, decimal value)
   {
     this.type = type;
     this.value = value;
   }
}
 
enum AccountValueType
{
  OneYearTurnover = 0,
  TwoYearTurnover,
  ThreeYearTurnover,
  TaxReturns
}