org.apache.flink.table.api

Interface FlatAggregateTable

@PublicEvolving
public interface FlatAggregateTable

A table that performs flatAggregate on a Table, a GroupedTable or a WindowGroupedTable.

Method Summary

Modifier and Type	Method and Description
Table	select(Expression... fields) Performs a selection operation on a FlatAggregateTable table.

Method Detail

select

Table select(Expression... fields)

Performs a selection operation on a FlatAggregateTable table. Similar to a SQL SELECT statement. The field expressions can contain complex expressions.

Note: You have to close the flatAggregate with a select statement. And the select statement does not support aggregate functions.

Example:

 tableEnv.createTemporarySystemFunction("tableAggFunc", MyTableAggregateFunction.class);
 tab.groupBy($("key"))
   .flatAggregate(call("tableAggFunc", $("a"), $("b")).as("x", "y", "z"))
   .select($("key"), $("x"), $("y"), $("z"));
 

Scala Example:

 val tableAggFunc: TableAggregateFunction = new MyTableAggregateFunction
 tab.groupBy($"key")
   .flatAggregate(tableAggFunc($"a", $"b") as ("x", "y", "z"))
   .select($"key", $"x", $"y", $"z")