toAppendStream doesn‘t support consuming update and delete changes which is produced by node

问题显示如下：

AppendStreamTableSink doesn't support consuming update changes which is produced by node GroupAggregate(groupBy=[province], select=[province, SUM(reg_num) AS reg_num])

执行的sql语句为

Table table =tableEnv.sqlQuery("select province,sum(reg_num) reg_num from map group by province")

结果输出是所使用的的转换流为toAppendStream

tEnv.toAppendStream(table, Row.class).print("res");

从字面意思看是因为节点连接产生的，toAppendStream不支持更、改、删。
另外个人认为这可能和我自己读取的是本地文件或者数据库这类支持增删改查的数据源也有关。
解决方式是：

tEnv.toRetractStream(table, Row.class).print("res");

Flink官网对这块流表转换做了解释：https://nightlies.apache.org/flink/flink-docs-release-1.13/zh/docs/dev/table/concepts/dynamic_tables/

希望这篇文章对你有所帮助，也希望大家能反馈自己的心得见解。