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ASF GitHub Bot commented on FLINK-2828: --------------------------------------- Github user twalthr commented on a diff in the pull request: https://github.com/apache/flink/pull/1237#discussion_r43872771 --- Diff: flink-staging/flink-table/src/main/scala/org/apache/flink/api/table/expressions/analysis/FieldBacktracker.scala --- @@ -0,0 +1,79 @@ +/* + * 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.api.table.expressions.analysis + +import org.apache.flink.api.table.expressions.{Naming, ResolvedFieldReference} +import org.apache.flink.api.table.input.{AdaptiveTableSource, TableSource} +import org.apache.flink.api.table.plan._ + +object FieldBacktracker { + + /** + * Tracks a field back to its Root and returns its original name and AdaptiveTableSource + * if possible. + * This only happens if the field is forwarded unmodified. Renaming operations are reverted. + * + * @param op start operator + * @param fieldName field name at start operator + * @return original field name with corresponding AdaptiveTableSource + */ + def resolveFieldNameAndTableSource(op: PlanNode, fieldName: String): + Option[(AdaptiveTableSource, String)] = { + op match { + case s@Select(input, selection) => + var resolvedField: Option[(AdaptiveTableSource, String)] = None + // only follow unmodified fields + selection.foreach(expr => { + if (resolvedField.isEmpty) { + expr match { + case ResolvedFieldReference(name, _) if name == fieldName => + resolvedField = resolveFieldNameAndTableSource(input, fieldName) + case n@Naming(ResolvedFieldReference(oldName, _), newName) if newName == fieldName => + resolvedField = resolveFieldNameAndTableSource(input, oldName) + case _ => // do nothing + } + } + }) --- End diff -- Build was successful (at least my parts). Do you think I can merge it? > Add interfaces for Table API input formats > ------------------------------------------ > > Key: FLINK-2828 > URL: https://issues.apache.org/jira/browse/FLINK-2828 > Project: Flink > Issue Type: New Feature > Components: Table API > Reporter: Timo Walther > Assignee: Timo Walther > > In order to support input formats for the Table API, interfaces are > necessary. I propose two types of TableSources: > - AdaptiveTableSources can adapt their output to the requirements of the > plan. Although the output schema stays the same, the TableSource can react on > field resolution and/or predicates internally and can return adapted > DataSet/DataStream versions in the "translate" step. > - StaticTableSources are an easy way to provide the Table API with additional > input formats without much implementation effort (e.g. for fromCsvFile()) > TableSources need to be deeply integrated into the Table API. > The TableEnvironment requires a newly introduced AbstractExecutionEnvironment > (common super class of all ExecutionEnvironments for DataSets and > DataStreams). > Here's what a TableSource can see from more complicated queries: > {code} > getTableJava(tableSource1) > .filter("a===5 || a===6") > .select("a as a4, b as b4, c as c4") > .filter("b4===7") > .join(getTableJava(tableSource2)) > .where("a===a4 && c==='Test' && c4==='Test2'") > // Result predicates for tableSource1: > // List("a===5 || a===6", "b===7", "c==='Test2'") > // Result predicates for tableSource2: > // List("c==='Test'") > // Result resolved fields for tableSource1 (true = filtering, > false=selection): > // Set(("a", true), ("a", false), ("b", true), ("b", false), ("c", false), > ("c", true)) > // Result resolved fields for tableSource2 (true = filtering, > false=selection): > // Set(("a", true), ("c", true)) > {code} -- This message was sent by Atlassian JIRA (v6.3.4#6332)