org.apache.flink.table.planner.catalog.SqlCatalogViewTable Maven / Gradle / Ivy

/*
 * 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.table.planner.catalog;

import org.apache.flink.table.catalog.CatalogView;
import org.apache.flink.table.planner.plan.schema.ExpandingPreparingTable;
import org.apache.flink.table.planner.plan.stats.FlinkStatistic;

import org.apache.calcite.plan.RelOptSchema;
import org.apache.calcite.plan.RelOptUtil;
import org.apache.calcite.rel.RelNode;
import org.apache.calcite.rel.type.RelDataType;

import javax.annotation.Nullable;

import java.util.List;

/**
 * A bridge between a Flink's specific {@link CatalogView} and a Calcite's {@link
 * org.apache.calcite.plan.RelOptTable}. It implements parsing and conversion from sql string to
 * {@link org.apache.calcite.rel.RelNode}.
 */
public class SqlCatalogViewTable extends ExpandingPreparingTable {
    private final CatalogView view;
    private final List viewPath;

    public SqlCatalogViewTable(
            @Nullable RelOptSchema relOptSchema,
            RelDataType rowType,
            Iterable names,
            FlinkStatistic statistic,
            CatalogView view,
            List viewPath) {
        super(relOptSchema, rowType, names, statistic);
        this.view = view;
        this.viewPath = viewPath;
    }

    @Override
    public RelNode convertToRel(ToRelContext context) {
        RelNode original =
                context.expandView(rowType, view.getExpandedQuery(), viewPath, names).project();
        return RelOptUtil.createCastRel(original, rowType, true);
    }
}