dawidwys commented on a change in pull request #8585: [FLINK-12690][table-api] Introduce a Planner interface URL: https://github.com/apache/flink/pull/8585#discussion_r291161530
########## File path: flink-table/flink-table-api-java/src/main/java/org/apache/flink/table/operations/ModifyOperation.java ########## @@ -0,0 +1,52 @@ +/* + * 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.operations; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.table.api.QueryConfig; +import org.apache.flink.table.api.TableSchema; + +import java.util.List; + +/** + * A {@link TableOperation} that describes the DML queries such as e.g. INSERT or conversion to a + * DataStream. + * + * <p>A tree of {@link QueryOperation} with a {@link ModifyOperation} on top + * represents a runnable query that can be transformed into a graph of + * {@link org.apache.flink.streaming.api.transformations.StreamTransformation} + * via {@link org.apache.flink.table.planner.Planner#translate(List, QueryConfig)} + * + * <p>It extends from {@link QueryOperation} to enable applying subsequent + * {@link QueryOperation}s on top. In other words it makes it possible to have an output + * transformation as a middle step of a relational query. This is not supported yet. + * + * @see QueryOperation + */ +@Internal +public abstract class ModifyOperation extends QueryOperation { Review comment: I didn't mean `write data to a sink and then read it again`. What I meant is something as follows: you write data to sink and the output of the operation is e.g. the number of rows stored (this is the standard SQL behavior), or e.g. id of record in an external DB. Ad. "does DML is a DQL" actually there are quite a few different opinions. The most prominent is that SELECT(DQL) is also a DML, but if you think about a query like `SELECT * FROM INSERT INTO` it may be considered also the other way round. ---------------------------------------------------------------- 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
