并发情况下，执行select语句用加上事务属性吗？

public SqlDataReader executeQuery(string sql)
{
    SqlCommand command = this.connection.CreateCommand();
    command.CommandText = sql;
    command.CommandType = CommandType.Text;
    if (this.trans.getSqlTrans() != null)
    {
        command.Transaction = this.trans.getSqlTrans();
    }
    return command.ExecuteReader();
}