| // 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.impala.analysis; |
| |
| import org.apache.impala.common.AnalysisException; |
| import org.apache.impala.thrift.TExprNode; |
| |
| import com.google.common.base.Preconditions; |
| |
| /** |
| * Class representing a [NOT] EXISTS predicate. |
| */ |
| public class ExistsPredicate extends Predicate { |
| private boolean notExists_ = false; |
| |
| public boolean isNotExists() { return notExists_; } |
| |
| /** |
| * C'tor that initializes an ExistsPredicate from a Subquery. |
| */ |
| public ExistsPredicate(Subquery subquery, boolean notExists) { |
| Preconditions.checkNotNull(subquery); |
| children_.add(subquery); |
| notExists_ = notExists; |
| } |
| |
| @Override |
| public Expr negate() { |
| return new ExistsPredicate((Subquery)getChild(0), !notExists_); |
| } |
| |
| /** |
| * Copy c'tor used in clone. |
| */ |
| public ExistsPredicate(ExistsPredicate other) { |
| super(other); |
| notExists_ = other.notExists_; |
| } |
| |
| @Override |
| protected void analyzeImpl(Analyzer analyzer) throws AnalysisException { |
| super.analyzeImpl(analyzer); |
| ((Subquery)children_.get(0)).getStatement().setIsRuntimeScalar(false); |
| } |
| |
| @Override |
| protected void toThrift(TExprNode msg) { |
| // Cannot serialize a nested predicate |
| Preconditions.checkState(false); |
| } |
| |
| @Override |
| public boolean localEquals(Expr that) { |
| return super.localEquals(that) && notExists_ == ((ExistsPredicate)that).notExists_; |
| } |
| |
| @Override |
| public Expr clone() { return new ExistsPredicate(this); } |
| |
| @Override |
| protected float computeEvalCost() { return UNKNOWN_COST; } |
| |
| @Override |
| public String toSqlImpl(ToSqlOptions options) { |
| StringBuilder strBuilder = new StringBuilder(); |
| if (notExists_) strBuilder.append("NOT "); |
| strBuilder.append("EXISTS "); |
| strBuilder.append(getChild(0).toSql(options)); |
| return strBuilder.toString(); |
| } |
| } |