private void requestStmtId() throws SQLException {
    try {
      this.stmtId = client.requestStatementId(sessionId);
    } catch (TException e) {
      if (reConnect()) {
        try {
          this.stmtId = client.requestStatementId(sessionId);
        } catch (TException e2) {
          throw new SQLException(
              "Cannot get id for statement after reconnecting. please check server status", e2);
        }
      } else {
        throw new SQLException(
            "Cannot get id for statement after reconnecting. please check server status", e);
      }
    }
  }
There are two kinds of sql here: (1) query sql (2) update sql.

<p>(1) return IoTDBJDBCResultSet or IoTDBNonAlignJDBCResultSet (2) simply get executed
iotdb-client/jdbc/src/main/java/org/apache/iotdb/jdbc/IoTDBStatement.java