| /* |
| * 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.beam.sdk.extensions.sql.zetasql.translation; |
| |
| import com.google.zetasql.resolvedast.ResolvedNode; |
| import com.google.zetasql.resolvedast.ResolvedNodes.ResolvedWithRefScan; |
| import java.util.Collections; |
| import java.util.List; |
| import org.apache.beam.vendor.calcite.v1_20_0.org.apache.calcite.rel.RelNode; |
| |
| /** Converts a call-site reference to a named WITH subquery. */ |
| class WithRefScanConverter extends RelConverter<ResolvedWithRefScan> { |
| |
| WithRefScanConverter(ConversionContext context) { |
| super(context); |
| } |
| |
| @Override |
| public List<ResolvedNode> getInputs(ResolvedWithRefScan zetaNode) { |
| // WithRefScan contains only a name of a WITH query, |
| // but to actually convert it to the node we need to get the resolved node representation |
| // of the query. Here we take it from the trait, where it was persisted previously |
| // in WithScanConverter that actually parses the WITH query part. |
| // |
| // This query node returned from here will be converted by some other converter, |
| // (e.g. if the WITH query root is a projection it will go through ProjectScanConverter) |
| // and will reach the convert() method below as an already converted rel node. |
| return Collections.singletonList( |
| getTrait().withEntries.get(zetaNode.getWithQueryName()).getWithSubquery()); |
| } |
| |
| @Override |
| public RelNode convert(ResolvedWithRefScan zetaNode, List<RelNode> inputs) { |
| // Here the actual WITH query body has already been converted by, e.g. a ProjectScnaConverter, |
| // so to resolve the reference we just return that converter rel node. |
| return inputs.get(0); |
| } |
| } |