DRY data: Final version of Database.cs

Database.final.cs

public class Database
{
    private readonly string _connStr;

    private readonly DbProviderFactory _dpf;

    public Database(string connStr) : this(connStr,
      DbProviderFactories.GetFactory("System.Data.SqlClient"))
    { }

    public Database(string connStr, DbProviderFactory dpf)
    {
        _connStr = connStr;
        _dpf = dpf;
    }

    public IEnumerable<T> ExecuteReader<T>(string spName,
      Func<StoredProcedure, StoredProcedure> configure, 
      Func<IDataRecord, T> map)
    {
        return Execute(spName, configure, 
            cmd => cmd.ExecuteReader(),
            r =>
            {
                var result = new List<T>();
                while (r.Read())
                {
                    result.Add(map(r));
                }
                return result;
            });
    }

    public T ExecuteRow<T>(string spName,
      Func<StoredProcedure, StoredProcedure> configure, 
      Func<IDataRecord, T> map)
    {
        return ExecuteReader(spName, configure, map).First();
    }

    public T ExecuteScalar<T>(string spName,
      Func<StoredProcedure, StoredProcedure> configure, 
      Func<object, T> map)
    {
        return Execute(spName, configure,
            cmd => cmd.ExecuteScalar(), map);
    }

    public void ExecuteNonQuery(string spName,
      Func<StoredProcedure, StoredProcedure> configure)
    {
        Execute(spName, configure,
            cmd => cmd.ExecuteNonQuery(),
            o => o);
    }

    public TResult Execute<T, TResult>(string spName,
      Func<StoredProcedure, StoredProcedure> configure,
      Func<IDbCommand, T> execute,
      Func<T, TResult> map)
    {
        using (var conn = _dpf.CreateConnection())
        using (var cmd = _dpf.CreateCommand())
        {
            conn.ConnectionString = _connStr;
            conn.Open();
            cmd.Connection = conn;
            cmd.CommandType = CommandType.StoredProcedure;
            cmd.CommandText = spName;
            configure(new StoredProcedure(cmd, _dpf));
            cmd.CommandType = CommandType.StoredProcedure;
            return map(execute(cmd));
        }
    }
}