public JoinClause AddJoin(JoinType join, Table toTable, string toColumnName, Comparison @operator, Table fromTable, string fromColumnName)
        {
            JoinClause NewJoin = new JoinClause(join, toTable, toColumnName, @operator, fromTable, fromColumnName);
            _joins.Add(NewJoin);

            return NewJoin;
        }
 public JoinClause AddJoin(JoinClause newJoin)
 {
     _joins.Add(newJoin);
     return newJoin;
 }