Package org.apache.flink.table.api

Interface WindowGroupedTable

@PublicEvolving public interface WindowGroupedTable
A table that has been windowed and grouped for GroupWindows.

  • Method Summary

    Modifier and Type
    Method
    Description
    AggregatedTable
    aggregate(org.apache.flink.table.expressions.Expression aggregateFunction)
    Performs an aggregate operation on a window grouped table.
    FlatAggregateTable
    flatAggregate(org.apache.flink.table.expressions.Expression tableAggregateFunction)
    Performs a flatAggregate operation on a window grouped table.
    Table
    select(org.apache.flink.table.expressions.Expression... fields)
    Performs a selection operation on a window grouped table.

  • Method Details

    • select

      Table select(org.apache.flink.table.expressions.Expression... fields)
      Performs a selection operation on a window grouped table. Similar to an SQL SELECT statement. The field expressions can contain complex expressions and aggregations.

      Example: 

      
 windowGroupedTable.select($("key"), $("window").start(), $("value").avg().as("valavg"));

      Scala Example: 

      
 windowGroupedTable.select('key, 'window.start, 'value.avg as 'valavg)

    • aggregate

      AggregatedTable aggregate(org.apache.flink.table.expressions.Expression aggregateFunction)
      Performs an aggregate operation on a window grouped table. You have to close the aggregate(Expression) with a select statement. The output will be flattened if the output type is a composite type.

      Example: 

      
 windowGroupedTable.aggregate(call(MyAggregateFunction.class, $("a"), $("b")).as("x", "y", "z"))
   .select($("key"), $("window").start(), $("x"), $("y"), $("z"));

      Scala Example: 

      
 val aggFunc = new MyAggregateFunction
 windowGroupedTable
   .aggregate(aggFunc('a, 'b) as ('x, 'y, 'z))
   .select('key, 'window.start, 'x, 'y, 'z)

    • flatAggregate

      FlatAggregateTable flatAggregate(org.apache.flink.table.expressions.Expression tableAggregateFunction)
      Performs a flatAggregate operation on a window grouped table. FlatAggregate takes a TableAggregateFunction which returns multiple rows. Use a selection after flatAggregate.

      Example: 

      
 windowGroupedTable.flatAggregate(call(MyTableAggregateFunction.class, $("a"), $("b")).as("x", "y", "z"))
   .select($("key"), $("window").start(), $("x"), $("y"), $("z"));

      Scala Example: 

      
 val tableAggFunc = new MyTableAggregateFunction
 windowGroupedTable
   .flatAggregate(tableAggFunc('a, 'b) as ('x, 'y, 'z))
   .select('key, 'window.start, 'x, 'y, 'z)