core/src/main/java/org/apache/calcite/sql/validate/WithNamespace.java

/*
 * 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.calcite.sql.validate;

import org.apache.calcite.rel.type.RelDataType;
import org.apache.calcite.sql.SqlNode;
import org.apache.calcite.sql.SqlWith;
import org.apache.calcite.sql.SqlWithItem;
import org.apache.calcite.util.Util;

import org.checkerframework.checker.nullness.qual.Nullable;

import static java.util.Objects.requireNonNull;

/**
 * Namespace for <code>WITH</code> clause.
 */
public class WithNamespace extends AbstractNamespace {
  //~ Instance fields --------------------------------------------------------

  private final SqlWith with;

  //~ Constructors -----------------------------------------------------------

  /**
   * Creates a TableConstructorNamespace.
   *
   * @param validator     Validator
   * @param with          WITH clause
   * @param enclosingNode Enclosing node
   */
  WithNamespace(SqlValidatorImpl validator,
      SqlWith with,
      SqlNode enclosingNode) {
    super(validator, enclosingNode);
    this.with = with;
  }

  //~ Methods ----------------------------------------------------------------

  @Override protected RelDataType validateImpl(RelDataType targetRowType) {
    for (SqlNode withItem : with.withList) {
      validator.validateWithItem((SqlWithItem) withItem);
    }
    final SqlValidatorScope scope2 =
        validator.getWithScope(Util.last(with.withList));
    final SqlValidatorNamespace bodyNamespace =
        requireNonNull(validator.getNamespace(with.body), "namespace");

    validator.validateQuery(with.body, scope2, targetRowType);
    final RelDataType rowType = validator.getValidatedNodeType(with.body);
    validator.setValidatedNodeType(with, rowType);
    mustFilterFields = bodyNamespace.getMustFilterFields();
    return rowType;
  }

  @Override public @Nullable SqlNode getNode() {
    return with;
  }
}