if (log.isDebugEnabled()) {

      log.debug("invoke execute, sql = " + sql);

    }

    if (sqlType == SqlType.SELECT || sqlType == SqlType.SELECT_FOR_UPDATE || sqlType == SqlType.SHOW) {

      executeQuery();

      return true;

    } else if (sqlType == SqlType.INSERT || sqlType == SqlType.UPDATE || sqlType == SqlType.DELETE||sqlType == SqlType.REPLACE

        ||sqlType==SqlType.TRUNCATE|| sqlType == SqlType.CREATE|| sqlType== SqlType.DROP|| sqlType == SqlType.LOAD|| sqlType== SqlType.MERGE) {

  public static SqlType getSqlType(String sql) throws SQLException {

    //#bug 2011-11-24,modify by junyu,�Ȳ��߻��棬����sql�仯�޴󣬻��滻�뻻��̫�࣬gc̫����

//    SqlType sqlType = globalCache.getSqlType(sql);

//    if (sqlType == null) {

    //#bug 2011-12-8,modify by junyu ,this code use huge cpu resource,and most

    //sql have no comment,so first simple look for there whether have the comment

    String noCommentsSql=sql;

    if(sql.contains("/*")){

      noCommentsSql = StringUtils.stripComments(sql, "'\"", "'\"", true, false, true, true).trim();

  //jdbc�淶: ����true��ʾexecuteQuery��false��ʾexecuteUpdate

  private boolean executeInternal(String sql, int autoGeneratedKeys, int[] columnIndexes, String[] columnNames)

      throws SQLException {

    if (sqlType == SqlType.SELECT || sqlType == SqlType.SELECT_FOR_UPDATE || sqlType == SqlType.SHOW) {

      executeQuery(sql);

      return true;

    } else if (sqlType == SqlType.INSERT || sqlType == SqlType.UPDATE || sqlType == SqlType.DELETE||sqlType == SqlType.REPLACE||sqlType == SqlType.TRUNCATE

        || sqlType == SqlType.CREATE|| sqlType== SqlType.DROP|| sqlType == SqlType.LOAD|| sqlType== SqlType.MERGE) {