Quadcap Embeddable Database

com/quadcap/sql/PrimaryKeyConstraint.java

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package com.quadcap.sql;

/* Copyright 1999 - 2003 Quadcap Software.  All rights reserved.
 *
 * This software is distributed under the Quadcap Free Software License.
 * This software may be used or modified for any purpose, personal or
 * commercial.  Open Source redistributions are permitted.  Commercial
 * redistribution of larger works derived from, or works which bundle
 * this software requires a "Commercial Redistribution License"; see
 * http://www.quadcap.com/purchase.
 *
 * Redistributions qualify as "Open Source" under  one of the following terms:
 *   
 *    Redistributions are made at no charge beyond the reasonable cost of
 *    materials and delivery.
 *
 *    Redistributions are accompanied by a copy of the Source Code or by an
 *    irrevocable offer to provide a copy of the Source Code for up to three
 *    years at the cost of materials and delivery.  Such redistributions
 *    must allow further use, modification, and redistribution of the Source
 *    Code under substantially the same terms as this license.
 *
 * Redistributions of source code must retain the copyright notices as they
 * appear in each source code file, these license terms, and the
 * disclaimer/limitation of liability set forth as paragraph 6 below.
 *
 * Redistributions in binary form must reproduce this Copyright Notice,
 * these license terms, and the disclaimer/limitation of liability set
 * forth as paragraph 6 below, in the documentation and/or other materials
 * provided with the distribution.
 *
 * The Software is provided on an "AS IS" basis.  No warranty is
 * provided that the Software is free of defects, or fit for a
 * particular purpose.  
 *
 * Limitation of Liability. Quadcap Software shall not be liable
 * for any damages suffered by the Licensee or any third party resulting
 * from use of the Software.
 */

import java.io.ByteArrayOutputStream;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;

import java.util.Vector;

import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;

import com.quadcap.sql.types.Value;

import com.quadcap.sql.io.ObjectInputStream;
import com.quadcap.sql.io.ObjectOutputStream;

import com.quadcap.sql.index.Btree;

import com.quadcap.sql.file.BlockFile;

import com.quadcap.util.Debug;
import com.quadcap.util.Util;

/**
 * Index constraint for <b>PRIMARY KEY</b>s.
 *
 * @author Stan Bailes
 */
public class PrimaryKeyConstraint extends UniqueConstraint
                                  implements Externalizable {
    /**
     * Default constructor
     */
    public PrimaryKeyConstraint() {}

    /**
     * Explicit constructor for single column constraint, taking column name.
     */
    public PrimaryKeyConstraint(String name) {
        super(name);
    }

    /**
     * Explicit constructor for multiple column constraint with specified
     * constraint name and column names
     */
    public PrimaryKeyConstraint(String name, Vector names) {
        super(name, names);
    }

    /**
     * Read me from a stream
     *
     * @exception IOException may be thrown
     */
    public void readExternal(ObjectInput in)
        throws IOException, ClassNotFoundException
    {
        super.readExternal(in);
    }

    /**
     * Write me to a stream
     *
     * @exception IOException may be thrown
     */
    public void writeExternal(ObjectOutput out) throws IOException {
        super.writeExternal(out);
    }

    /**
     * Return the number of columns in the index
     */
    public int getIndexColumnCount() {
        return getColumnCount();
    }

    /**
     * IndexConstraint.makeKey()  I use the column(s) I was given
     */
    public byte[] makeKey(Session session, Row row, long rowId)
        throws SQLException
    {
        return Key.makeKey(table, row, getColumns(), 0, false);
    }

    /**
     * Yes, I *am* the primary key constraint.
     */
    public String constraintType() { return "primary key"; }

    /**
     * Let me tell you what you've going to do...
     */
    public void setTable(Table t) throws SQLException {
        super.setTable(t);
        int[] cols = getColumns();
        final int notnull = ResultSetMetaData.columnNoNulls;
        for (int i = 0; i < cols.length; i++) {
            t.getColumn(cols[i]).setNullable(notnull);
        }
    }
}