Dataklass för SQL Server

C#-Code:

namespace CRS
{
    public class Data : System.IDisposable
    {
        private System.Data.SqlClient.SqlCommand _command;
        private System.Data.SqlClient.SqlConnection _connection;

        public Data()
        {
            _connection = new System.Data.SqlClient.SqlConnection();
            _connection.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
            _connection.Open();
            _command = _connection.CreateCommand();
        }

        public void AddParameter(string name, System.Data.DbType type, object value)
        {
            System.Data.SqlClient.SqlParameter param = new System.Data.SqlClient.SqlParameter();
            param.ParameterName = name;
            param.DbType = type;
            param.Value = value;
            _command.Parameters.Add(param);
        }

        public string CommandText
        {
            get { return this._command.CommandText; }
            set { this._command.CommandText = value; }
        }

        public System.Data.IDbCommand Command
        {
            get{ return this._command;}
        }

        public System.Data.IDataReader ExecuteReader()
        {
            return this._command.ExecuteReader();
        }

        public void ExecuteNonQuery()
        {
            this._command.ExecuteNonQuery();
        }

        public object ExecuteScalar()
        {
            return this._command.ExecuteScalar();
        }

        public void Dispose()
        {
            _connection.Close();
            _command.Dispose();
            _connection.Dispose();
        }
    }
} 

C#-Code:

IDataReader reader;
using (CRS.Data data = new CRS.Data())
{
    data.CommandText = "SELECT * FROM tabell WHERE id=@id";
    data.AddParameter("@id", DbType.Int32, 1);
    reader = data.ExecuteReader();
}