org.sql.generation.api.grammar.definition.table.ReferentialAction Maven / Gradle / Ivy

/*
 * Copyright (c) 2010, Stanislav Muhametsin. All Rights Reserved.
 *
 * Licensed 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.sql.generation.api.grammar.definition.table;

/**
 * This enum represents the five referential actions of SQL. These are {@link #CASCADE}, {@link #SET_NULL},
 * {@link #SET_DEFAULT}, {@link #RESTRICT}, and {@link #NO_ACTION}.
 * 
 * @author Stanislav Muhametsin
 */
public final class ReferentialAction
{

    /**
     * Represents the cascading policy ({@code CASCADE}.
     */
    public static final ReferentialAction CASCADE = new ReferentialAction();

    /**
     * Represents the policy, which sets the value as {@code NULL} ({@code SET NULL}.
     */
    public static final ReferentialAction SET_NULL = new ReferentialAction();

    /**
     * Represents the policy, which sets the value as default ({@code SET DEFAULT}.
     */
    public static final ReferentialAction SET_DEFAULT = new ReferentialAction();

    /**
     * Represents the policy, which checks the integrity before {@code UPDATE} or {@code DELETE} statement, and
     * the statement will not be executed if it violates integrity.
     */
    public static final ReferentialAction RESTRICT = new ReferentialAction();

    /**
     * Represents the policy, which checks the integrity after {@code UPDATE} or {@code DELETE} statement, and
     * the statement will not be executed if it violates integrity.
     */
    public static final ReferentialAction NO_ACTION = new ReferentialAction();
}