constraint.java

hsql是很有名的嵌入式数据库

/* Copyright (c) 1995-2000, The Hypersonic SQL Group.
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 *
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 * modification, are permitted provided that the following conditions are met:
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 * Redistributions in binary form must reproduce the above copyright notice,
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 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * This software consists of voluntary contributions made by many individuals 
 * on behalf of the Hypersonic SQL Group.
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 * For work added by the HSQL Development Group:
 *
 * Copyright (c) 2001-2005, The HSQL Development Group
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of the HSQL Development Group nor the names of its
 * contributors may be used to endorse or promote products derived from this
 * software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
 * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */


package org.hsqldb;

import org.hsqldb.HsqlNameManager.HsqlName;
import org.hsqldb.index.RowIterator;
import org.hsqldb.lib.ArrayUtil;
import org.hsqldb.lib.Iterator;

// fredt@users 20020225 - patch 1.7.0 by boucherb@users - named constraints
// fredt@users 20020320 - doc 1.7.0 - update
// tony_lai@users 20020820 - patch 595156 - violation of Integrity constraint name

/**
 * Implementation of a table constraint with references to the indexes used
 * by the constraint.<p>
 *
 * @author Thomas Mueller (Hypersonic SQL Group)
 * @version 1.8.0
 * @since Hypersonic SQL
 */
class Constraint {

    /*
     SQL CLI codes

     Referential Constraint 0 CASCADE
     Referential Constraint 1 RESTRICT
     Referential Constraint 2 SET NULL
     Referential Constraint 3 NO ACTION
     Referential Constraint 4 SET DEFAULT
     */
    static final int CASCADE        = 0,
                     SET_NULL       = 2,
                     NO_ACTION      = 3,
                     SET_DEFAULT    = 4,
                     INIT_DEFERRED  = 5,
                     INIT_IMMEDIATE = 6,
                     NOT_DEFERRABLE = 7;
    static final int FOREIGN_KEY    = 0,
                     MAIN           = 1,
                     UNIQUE         = 2,
                     CHECK          = 3,
                     PRIMARY_KEY    = 4;
    ConstraintCore   core;
    HsqlName         constName;
    int              constType;

    /**
     *  Constructor declaration for UNIQUE
     */
    Constraint(HsqlName name, Table t, Index index) {

        core           = new ConstraintCore();
        constName      = name;
        constType      = UNIQUE;
        core.mainTable = t;
        core.mainIndex = index;
        /* fredt - in unique constraints column list for iColMain is the
           visible columns of iMain
         */
        core.mainColArray = ArrayUtil.arraySlice(index.getColumns(), 0,
                index.getVisibleColumns());
        core.colLen = core.mainColArray.length;
    }

    /**
     *  Constructor for main constraints (foreign key references in PK table)
     */
    Constraint(HsqlName name, Constraint fkconstraint) {

        constName = name;
        constType = MAIN;
        core      = fkconstraint.core;
    }

    /**
     *  Constructor for foreign key constraints.
     *
     * @param  pkname name in the main (referenced) table, used internally
     * @param  fkname name in the referencing table, public name of the constraint
     * @param  main referenced table
     * @param  ref referencing talbe
     * @param  colmain array of column indexes in main table
     * @param  colref array of column indexes in referencing table
     * @param  imain index on the main table
     * @param  iref index on the referencing table
     * @param  deleteAction triggered action on delete
     * @param  updateAction triggered action on update
     * @exception  HsqlException
     */
    Constraint(HsqlName pkname, HsqlName fkname, Table main, Table ref,
               int[] colmain, int[] colref, Index imain, Index iref,
               int deleteAction, int updateAction) throws HsqlException {

        core           = new ConstraintCore();
        core.pkName    = pkname;
        core.fkName    = fkname;
        constName      = fkname;
        constType      = FOREIGN_KEY;
        core.mainTable = main;
        core.refTable  = ref;
        /* fredt - in FK constraints column lists for iColMain and iColRef have
           identical sets to visible columns of iMain and iRef respectively
           but the order of columns can be different and must be preserved
         */
        core.mainColArray = colmain;
        core.colLen       = core.mainColArray.length;
        core.refColArray  = colref;
        core.mainIndex    = imain;
        core.refIndex     = iref;
        core.deleteAction = deleteAction;
        core.updateAction = updateAction;
    }

    /**
     * temp constraint constructor
     */
    Constraint(HsqlName name, int[] mainCol, Table refTable, int[] refCol,
               int type, int deleteAction, int updateAction) {

        core              = new ConstraintCore();
        constName         = name;
        constType         = type;
        core.mainColArray = mainCol;
        core.refTable     = refTable;
        core.refColArray  = refCol;
        core.deleteAction = deleteAction;
        core.updateAction = updateAction;
    }

    private Constraint() {}

    /**
     * Returns the HsqlName.
     */
    HsqlName getName() {
        return constName;
    }

    /**
     * Changes constraint name.
     */
    private void setName(String name, boolean isquoted) throws HsqlException {
        constName.rename(name, isquoted);
    }

    /**
     *  probably a misnomer, but DatabaseMetaData.getCrossReference specifies
     *  it this way (I suppose because most FKs are declared against the PK of
     *  another table)
     *
     *  @return name of the index refereneced by a foreign key
     */
    String getPkName() {
        return core.pkName == null ? null
                                   : core.pkName.name;
    }

    /**
     *  probably a misnomer, but DatabaseMetaData.getCrossReference specifies
     *  it this way (I suppose because most FKs are declared against the PK of
     *  another table)
     *
     *  @return name of the index for the referencing foreign key
     */
    String getFkName() {
        return core.fkName == null ? null
                                   : core.fkName.name;
    }

    /**
     *  Returns the type of constraint
     */
    int getType() {
        return constType;
    }

    /**
     *  Returns the main table
     */
    Table getMain() {
        return core.mainTable;
    }

    /**
     *  Returns the main index
     */
    Index getMainIndex() {
        return core.mainIndex;
    }

    /**
     *  Returns the reference table
     */
    Table getRef() {
        return core.refTable;
    }

    /**
     *  Returns the reference index
     */
    Index getRefIndex() {
        return core.refIndex;
    }

    /**
     *  The ON DELETE triggered action of (foreign key) constraint
     */
    int getDeleteAction() {
        return core.deleteAction;
    }

    /**
     *  The ON UPDATE triggered action of (foreign key) constraint
     */
    int getUpdateAction() {
        return core.updateAction;
    }

    /**
     *  Returns the main table column index array
     */
    int[] getMainColumns() {
        return core.mainColArray;
    }

    /**
     *  Returns the reference table column index array
     */
    int[] getRefColumns() {
        return core.refColArray;
    }

    /**
     *  Returns true if an index is part this constraint and the constraint is set for
     *  a foreign key. Used for tests before dropping an index.
     */
    boolean isIndexFK(Index index) {

        if (constType == FOREIGN_KEY || constType == MAIN) {
            if (core.mainIndex == index || core.refIndex == index) {
                return true;
            }
        }

        return false;
    }

    /**