flink sql窗口api

Question

我尝试使用flink sql窗口API:https://ci.apache.org/projects/flink/flink-docs-release-1.3/dev/table_api.html#group-windows

StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
StreamTableEnvironment tableEnv = TableEnvironment.getTableEnvironment(env);

// ingest a DataStream from an external source
DataStream<Tuple3<Long, String, Integer>> ds = env.addSource(...);
// register the DataStream as table "Orders"
tableEnv.registerDataStream("Orders", ds, "user, product, amount");

// compute SUM(amount) per day (in event-time)
Table result1 = tableEnv.sql(
  "SELECT user, " +
  "  TUMBLE_START(rowtime(), INTERVAL '1' DAY) as wStart,  " +
  "  SUM(amount) FROM Orders " + 
  "GROUP BY TUMBLE(rowtime(), INTERVAL '1' DAY), user");

Answer 1

目前这些文档有点不同步，但社区正在一个单独的分支中进行处理。Flink1.3引入了所谓的“时间属性”，以便在将来更明确地访问、表达和使用时间。

您可以在当前文档草稿中找到更多信息。在这里可以找到一些如何在表程序中使用时间属性的示例。