Flink Sql -- toAppendStream doesn‘t support consuming update and delete changes which

stay Flink sql Test output , Want to put sql Result of query Table To DataStream And then print

When we table.toAppendStream[Row] When Found an error

Actually, this is because we sql Look up the dynamic table yes Mysql Such sources , They can do update,delete,insert Operation of the .

about toAppendStream Well Yes, only the appended stream can be converted and output such as kafka

So we use

table.toRetractStream[Row].print() that will do
The printing result is a two-part operation , The front part is boolean type , The back is yours select among true Express insert ,false Express update/delete

 table.toRetractStream[Row].print()   that will do  
 tableEnv.toRetractStream(table,EventLog.class).print();

about Table / sql turn Stream You can also see the official website for detailed explanations
Official website