GroupWindowedTable (Flink : Table : API Java 2.0-preview1 API)

@PublicEvolving
public interface GroupWindowedTable

A table that has been windowed for GroupWindows.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`WindowGroupedTable`	`groupBy(org.apache.flink.table.expressions.Expression... fields)`	Groups the elements by a mandatory window and one or more optional grouping attributes.

- Method Detail
  - groupBy
```
WindowGroupedTable groupBy(org.apache.flink.table.expressions.Expression... fields)
```
    Groups the elements by a mandatory window and one or more optional grouping attributes. The window is specified by referring to its alias.
    If no additional grouping attribute is specified and if the input is a streaming table, the aggregation will be performed by a single task, i.e., with parallelism 1.
    Aggregations are performed per group and defined by a subsequent select(...) clause similar to SQL SELECT-GROUP-BY query.
    Example:
    tab.window([groupWindow].as("w")).groupBy($("w"), $("key")).select($("key"), $("value").avg());
    
    Scala Example:
    tab.window([groupWindow] as 'w)).groupBy('w, 'key).select('key, 'value.avg)