dawidwys commented on a change in pull request #8006: [FLINK-11068][table] Convert the API classes of *Table to interfaces URL: https://github.com/apache/flink/pull/8006#discussion_r266766736
########## File path: flink-table/flink-table-api-java/src/main/java/org/apache/flink/table/api/GroupedTable.java ########## @@ -0,0 +1,57 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +package org.apache.flink.table.api; + +import org.apache.flink.annotation.PublicEvolving; +import org.apache.flink.table.expressions.Expression; + +/** + * A table that has been grouped on a set of grouping keys. + */ +@PublicEvolving +public interface GroupedTable { + + /** + * Performs a selection operation on a grouped table. Similar to an SQL SELECT statement. + * The field expressions can contain complex expressions and aggregations. + * + * <p>Example: + * + * <pre> + * {@code + * tab.groupBy("key").select("key, value.avg + ' The average' as average") + * } + * </pre> + */ + Table select(String fields); + + /** + * Performs a selection operation on a grouped table. Similar to an SQL SELECT statement. + * The field expressions can contain complex expressions and aggregations. + * + * <p>Example: Review comment: Scala example:? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
