/*
 *
 * The DbUnit Database Testing Framework
 * Copyright (C)2005, DbUnit.org
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

package org.dbunit.database.search;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.dbunit.util.search.Edge;

/**
 * Implementation of an edge representing a foreign key (FK)  relationship between two
 * tables.<br>
 * The <code>from</code> node is the table which have the FK, while the 
 * <code>to</code> node is the table with the PK. In other words, the edge
 * A->B means FK(A) = PK(B).<br>
 * 
 * <strong>NOTE:</strong> only single-column PKs are supported at this moment
 *  
 * @author Felipe Leme <dbunit@felipeal.net>
 * @version $Revision: 554 $
 * @since Sep 9, 2005
 */

public class ForeignKeyRelationshipEdge extends Edge {

    /**
     * Logger for this class
     */
    private static final Logger logger = LoggerFactory.getLogger(ForeignKeyRelationshipEdge.class);

  private String fkColumn;
  private String pkColumn;
  
  /**
   * Creates an edge representing a FK.
   * @param tableFrom table that has the FK
   * @param tableTo table that has the PK
   * @param fkColumn name of the FK column on tableFrom
   * @param pkColumn name of the PK column on tableTo
   */
  
  public ForeignKeyRelationshipEdge(String tableFrom, String tableTo, String fkColumn, String pkColumn) {
    super(tableFrom, tableTo);
    this.fkColumn = fkColumn;
    this.pkColumn = pkColumn;
  }

  /**
   * Gets the name of the foreign key column in the relationship.
   * @return name of the foreign key column in the relationship.
   */
  public String getFKColumn() {
        logger.debug("getFKColumn() - start");

    return fkColumn;
  }
  
  /**
   * Gets the name of the primary key column in the relationship.
   * @return name of the primary key column in the relationship.
   */
  public String getPKColumn() {
        logger.debug("getPKColumn() - start");

    return pkColumn;
  }
  
  public String toString() {
        logger.debug("toString() - start");

    return getFrom() + "(" + getFKColumn() + ")->" + getTo() + "(" + getPKColumn() + ")";
  }
  
}