Repository Pattern without LINQ or other ORM?

Question

Does it makes sense to use the Repository pattern without the use of LINQ or some other ORM? I am writing an application in MONO and using MySQL, was thinking of using the repo

Answer 1

Repository has nothing at all to do with IQueryable. What you are thinking of is the Rob Conory .net 3.5 take on the repository pattern, which is actually more of a data broker pattern.

A repository is responsible for returning objects, and deals with data access so that the rest of your application can remain ignorant of it.

You can see a very high level description on Martin Fowlers site

Answer 2

Sure. The repository is simply a pattern used by linq. You can provide any sort of data access you want through it. A project I work on uses repositories that deal with strongly typed DataSets.

Answer 3

It's absolutely possible. But you should move queries to repository site and implement one repository per class. For example:

public abstract class GenericRepository : IRepository {
    public virtual T Get<T>(Identity id) where T : PersistentDocument {
        using (IDbConnection connection = GetConnection())
        using(IDbCommand command = CreateGetCommand(id, connection)) {
            using (IDataReader reader = command.ExecuteReader()) {
                var mapper = DaHelper.GetMapper<T>();
                return mapper.Map(reader);
            }
        }
    }

    protected virtual IDbCommand CreateGetCommand(Identity id, IDbConnection connection) {
        IDbCommand command = connection.CreateCommand();
        command.CommandText = String.Format("SELECT * FROM {0} e WHERE e.id = ?", TableName);
        command.Parameters.Add(id.ToGuid());
        return command;
    }

    protected abstract string TableName { get; }
}

public class UserRepository: GenericRepository<User>, IUserRepository
{
    protected override string TableName { get { return "users"; } }

    public User GetByEmail(string email)
    {
        using (IDbConnection connection = GetConnection())
        using (IDbCommand command = connection.CreateCommand())
        {
            command.CommandText  = String.Format("SELECT * FROM {0} e WHERE e.email = ?", TableName);
            command.Parameters.Add(email);
            using (var reader = command.ExecuteReader())
                return DaHelper.GetMapper<T>().Map(reader);
        }
    }
}