How to properly implement the Strategy Pattern with two interfaces? - wcf

Question

I have created a service data access layer where there are multiple databases where data needs to come from.
I was doing fine with one database where I defined the memberRepository that contained member details. However, now I have to get session-related details that are stored in another database.
OprationContracts:
IMemberServices contains GetLoggedInBuddies(int profileID);
ISessionServices contains GetProfileIDFromSessionID(string sessionID);
My service class:
public class MemberService : IMemberService, ISessionServices
{
#region Strategy pattern configuration
//
// Member repo
//
private MemberRepository memberRepository;
public MemberService()
: this(new MemberRepository())
{ }
public MemberService(MemberRepository memberRepository)
{
this.memberRepository = memberRepository;
}
//
// Session repo
//
private SessionRepository sessionRepository;
public MemberService() : this(new SessionRepository()){}
public MemberService(SessionRepository sessionRepository)
{
this.sessionRepository = sessionRepository;
}
#endregion
/// <summary>
/// Session-related details are maintained in the Secondary database
/// </summary>
/// <param name="sessionID"></param>
/// <returns></returns>
public int GetProfileIDFromSessionID(string sessionID)
{
int sessionProfileID = sessionRepository.GetProfileDetailsFromSessionID(sessionRepository);
return sessionProfileID;
}
/// <summary>
/// Try profileID = 1150526
/// </summary>
/// <param name="profileID"></param>
public void GetLoggedInBuddies(int profileID)
{
memberRepository.GetLoggedInBuddies(profileID);
//return memberRepository.GetLoggedInBuddies(profileID);
}
The issue is that in the // Session Repo section, as I already have a constructor defined. I get that.
So basically in each method I want to do something like
MemberService useSessionRepo = new MemberService(SessionRepository);
useSessionRepo.GetProfileDetailsFromSessionID(...);
MemberService useMemberRepo = new MemberService(MemberRepository);
useMemberRepo.GetLoggedInBuddies(...);
Just need a hand putting this together.
Thanks.

Answer 1

I'm not sure about your issue, but you can use a ctor without param, and with param for each repo.
public MemberService()
{
this.memberRepository = new MemberRepository();
this.sessionRepository = new SessionRepository();
}

Answer 2

I created a central repository that accepts the name of the connection string of the database I want to connect to.
public abstract class DatabaseRepository : BaseRepository
{
static IDbConnection connection;
/// <summary>
/// Handles db connectivity as Dapper assumes an existing connection for all functions
/// Since this app uses three databases, pass in the connection string for the required db.
/// </summary>
/// <returns></returns>
protected static IDbConnection OpenConnection(string connectionStringName)
{
try
{
connection = new SqlConnection(WebConfigurationManager.ConnectionStrings[connectionStringName].ConnectionString);
//connection = SqlMapperUtil.GetOpenConnection(connectionStringName); // if we want to use the Dapper utility methods
connection.Open();
return connection;
}
catch (Exception ex)
{
ErrorLogging.Instance.Fatal(ex); // uses singleton for logging
return null;
}
}
.
.
.
Then in my service library, I make the connection to the appropriate db and perform whatever queries I need:
using (IDbConnection connection = OpenConnection("FirstDBConnectionString")) { ...