nlpcraft/src/main/scala/org/apache/nlpcraft/model/tools/sqlgen/NCSqlSchema.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.nlpcraft.model.tools.sqlgen;

import org.apache.nlpcraft.model.*;
import java.util.Collection;
import java.util.stream.*;

/**
 * Object presentation of SQL schema. This representation gives object model for the SQL metadata
 * that was extracted from RDBMS and added to the data model stub by {@link NCSqlModelGenerator} utility.
 * 
 * @see NCSqlSchemaBuilder#makeSchema(NCModel)
 */
public interface NCSqlSchema {
    /**
     * Gets collection of tables for this SQL schema.
     *
     * @return Collection of tables for this SQL schema.
     */
    Collection<NCSqlTable> getTables();

    /**
     * Gets collection of joins for this SQL schema.
     * 
     * @return Collection of joins for this SQL schema.
     */
    Collection<NCSqlJoin> getJoins();

    /**
     * Creates and returns collection of all SQL columns across all tables in given schema. It is
     * equivalent to:
     * <pre class="brush: java">
     *     return getTables().stream().flatMap(t -&gt; t.getColumns().stream()).collect(Collectors.toList());
     * </pre>
     *
     * @return Collection of all SQL columns across all tables in given schema.
     */
    default Collection<NCSqlColumn> getAllColumns() {
        return getTables().stream().flatMap(t -> t.getColumns().stream()).collect(Collectors.toList());
    }
}