seawinde commented on code in PR #26055: URL: https://github.com/apache/doris/pull/26055#discussion_r1382600380
########## fe/fe-core/src/main/java/org/apache/doris/nereids/trees/plans/visitor/PlanVisitors.java: ########## @@ -0,0 +1,84 @@ +// 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.doris.nereids.trees.plans.visitor; + +import org.apache.doris.nereids.trees.expressions.Alias; +import org.apache.doris.nereids.trees.expressions.ExprId; +import org.apache.doris.nereids.trees.expressions.NamedExpression; +import org.apache.doris.nereids.trees.expressions.Slot; +import org.apache.doris.nereids.trees.plans.Plan; + +import com.google.common.collect.ImmutableCollection; +import com.google.common.collect.ImmutableMultimap; +import com.google.common.collect.ImmutableSet; + +import java.util.ArrayList; +import java.util.List; +import java.util.stream.Collectors; + +/** + * This is the facade and factory for plan visitor + */ +public class PlanVisitors { + + /** + * Infer output column name when it refers an expression and not has an alias manually. + */ + public static class InferPlanOutputAlias extends DefaultPlanVisitor<Void, ImmutableMultimap<ExprId, Integer>> { + + private final List<Slot> currentOutputs; + private final List<NamedExpression> finalOutputs; + + public InferPlanOutputAlias(List<Slot> currentOutputs) { + this.currentOutputs = currentOutputs; + this.finalOutputs = new ArrayList<>(currentOutputs); + } + + @Override + public Void visit(Plan plan, ImmutableMultimap<ExprId, Integer> context) { + + List<NamedExpression> projects = plan.getExpressions().stream() + .filter(expression -> expression instanceof NamedExpression) + .map(NamedExpression.class::cast) + .collect(Collectors.toList()); + + ImmutableSet<ExprId> currentOutputExprIdSet = context.keySet(); + for (NamedExpression projectItem : projects) { + ExprId exprId = projectItem.getExprId(); + // Infer name when alias child is expression and alias's name is from child + if (currentOutputExprIdSet.contains(projectItem.getExprId()) + && projectItem instanceof Alias + && ((Alias) projectItem).isNameFromChild()) { Review Comment: Alias construct logical as following: ` public Expression visitUnboundAlias(UnboundAlias unboundAlias, CascadesContext context) { Expression child = unboundAlias.child().accept(this, context); if (unboundAlias.getAlias().isPresent()) { return new Alias(child, unboundAlias.getAlias().get()); } else if (child instanceof NamedExpression) { return new Alias(child, ((NamedExpression) child).getName()); } else { return new Alias(child); } }` if the alias name is set by child.toSql() we should infer the alias name. `isNameFromChild ` field identify the name is from child. Maybe we should add anther field to record the info. WDYT? -- 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. To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@doris.apache.org For additional commands, e-mail: commits-h...@doris.apache.org
