table.java

hsqldb是100％java实现的数据库,是一个开放源代码的JAVA数据库 l 具有标准的SQL语法和JAVA接口 l HSQLDB可以自由使用和分发 l 非常简洁和快速的

/* Copyright (c) 1995-2000, The Hypersonic SQL 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 Hypersonic SQL 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 THE HYPERSONIC SQL GROUP,
 * 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.
 *
 * This software consists of voluntary contributions made by many individuals 
 * on behalf of the Hypersonic SQL Group.
 *
 *
 * 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 java.io.IOException;

import org.hsqldb.HsqlNameManager.HsqlName;
import org.hsqldb.index.RowIterator;
import org.hsqldb.lib.ArrayUtil;
import org.hsqldb.lib.HashMappedList;
import org.hsqldb.lib.HashSet;
import org.hsqldb.lib.HsqlArrayList;
import org.hsqldb.lib.Iterator;
import org.hsqldb.lib.StringUtil;
import org.hsqldb.persist.CachedObject;
import org.hsqldb.persist.DataFileCache;
import org.hsqldb.persist.PersistentStore;
import org.hsqldb.rowio.RowInputInterface;
import org.hsqldb.store.ValuePool;

// fredt@users 20020130 - patch 491987 by jimbag@users - made optional
// fredt@users 20020405 - patch 1.7.0 by fredt - quoted identifiers
// for sql standard quoted identifiers for column and table names and aliases
// applied to different places
// fredt@users 20020225 - patch 1.7.0 - restructuring
// some methods moved from Database.java, some rewritten
// changes to several methods
// fredt@users 20020225 - patch 1.7.0 - ON DELETE CASCADE
// fredt@users 20020225 - patch 1.7.0 - named constraints
// boucherb@users 20020225 - patch 1.7.0 - multi-column primary keys
// fredt@users 20020221 - patch 513005 by sqlbob@users (RMP)
// tony_lai@users 20020820 - patch 595099 - user defined PK name
// tony_lai@users 20020820 - patch 595172 - drop constraint fix
// kloska@users 20021030 - patch 1.7.2 - ON UPDATE CASCADE | SET NULL | SET DEFAULT
// kloska@users 20021112 - patch 1.7.2 - ON DELETE SET NULL | SET DEFAULT
// fredt@users 20021210 - patch 1.7.2 - better ADD / DROP INDEX for non-CACHED tables
// fredt@users 20030901 - patch 1.7.2 - allow multiple nulls for UNIQUE columns
// fredt@users 20030901 - patch 1.7.2 - reworked IDENTITY support
// achnettest@users 20040130 - patch 878288 - bug fix for new indexes in memory tables by Arne Christensen
// boucherb@users 20040327 - doc 1.7.2 - javadoc updates
// boucherb@users 200404xx - patch 1.7.2 - proper uri for getCatalogName
// fredt@users 20050000 - 1.8.0 updates in several areas
// fredt@users 20050220 - patch 1.8.0 enforcement of DECIMAL precision/scale

/**
 *  Holds the data structures and methods for creation of a database table.
 *
 *
 * Extensively rewritten and extended in successive versions of HSQLDB.
 *
 * @author Thomas Mueller (Hypersonic SQL Group)
 * @version 1.8.0
 * @since Hypersonic SQL
 */
public class Table extends BaseTable {

    // types of table
    public static final int SYSTEM_TABLE    = 0;
    public static final int SYSTEM_SUBQUERY = 1;
    public static final int TEMP_TABLE      = 2;
    public static final int MEMORY_TABLE    = 3;
    public static final int CACHED_TABLE    = 4;
    public static final int TEMP_TEXT_TABLE = 5;
    public static final int TEXT_TABLE      = 6;
    public static final int VIEW            = 7;

// boucherb@users - for future implementation of SQL standard INFORMATION_SCHEMA
    static final int SYSTEM_VIEW = 8;

    // main properties
// boucherb@users - access changed in support of metadata 1.7.2
    public HashMappedList columnList;                 // columns in table
    private int[]         primaryKeyCols;             // column numbers for primary key
    private int[]         primaryKeyTypes;            // types for primary key
    private int[]         primaryKeyColsSequence;     // {0,1,2,...}
    int[]                 bestRowIdentifierCols;      // column set for best index
    boolean               bestRowIdentifierStrict;    // true if it has no nullable column
    int[]                 bestIndexForColumn;         // index of the 'best' index for each column
    Index                 bestIndex;                  // the best index overall - null if there is no user-defined index
    int            identityColumn;                    // -1 means no such row
    NumberSequence identitySequence;                  // next value of identity column
    NumberSequence rowIdSequence;                     // next value of optional rowid

// -----------------------------------------------------------------------
    Constraint[]      constraintList;                 // constrainst for the table
    HsqlArrayList[]   triggerLists;                   // array of trigger lists
    private int[]     colTypes;                       // fredt - types of columns
    private int[]     colSizes;                       // fredt - copy of SIZE values for columns
    private int[]     colScales;                      // fredt - copy of SCALE values for columns
    private boolean[] colNullable;                    // fredt - modified copy of isNullable() values
    private Expression[] colDefaults;                 // fredt - expressions of DEFAULT values
    private int[]        defaultColumnMap;            // fred - holding 0,1,2,3,...
    private boolean      hasDefaultValues;            //fredt - shortcut for above
    boolean              sqlEnforceSize;              // inherited from the database -

    // properties for subclasses
    protected int           columnCount;              // inclusive the hidden primary key
    public Database         database;
    protected DataFileCache cache;
    protected HsqlName      tableName;                // SQL name
    private int             tableType;
    protected boolean       isReadOnly;
    protected boolean       isTemp;
    protected boolean       isCached;
    protected boolean       isText;
    protected boolean       isMemory;
    private boolean         isView;
    protected boolean       isLogged;
    protected int           indexType;                // fredt - type of index used
    protected boolean       onCommitPreserve;         // for temp tables

    //
    PersistentStore rowStore;
    Index[]         indexList;                        // vIndex(0) is the primary key index

    /**
     *  Constructor
     *
     * @param  db
     * @param  name
     * @param  type
     * @param  sessionid
     * @exception  HsqlException
     */
    Table(Database db, HsqlName name, int type) throws HsqlException {

        database         = db;
        sqlEnforceSize   = db.sqlEnforceStrictSize;
        identitySequence = new NumberSequence(null, 0, 1, Types.BIGINT);
        rowIdSequence    = new NumberSequence(null, 0, 1, Types.BIGINT);

        switch (type) {

            case SYSTEM_SUBQUERY :
                isTemp   = true;
                isMemory = true;
            case SYSTEM_TABLE :
                isMemory = true;
                break;

            case CACHED_TABLE :
                if (DatabaseURL.isFileBasedDatabaseType(db.getType())) {
                    cache     = db.logger.getCache();
                    isCached  = true;
                    isLogged  = !database.isFilesReadOnly();
                    indexType = Index.DISK_INDEX;
                    rowStore  = new RowStore();

                    break;
                }

                type = MEMORY_TABLE;
            case MEMORY_TABLE :
                isMemory = true;
                isLogged = !database.isFilesReadOnly();
                break;

            case TEMP_TABLE :
                isMemory = true;
                isTemp   = true;
                break;

            case TEMP_TEXT_TABLE :
                if (!DatabaseURL.isFileBasedDatabaseType(db.getType())) {
                    throw Trace.error(Trace.DATABASE_IS_MEMORY_ONLY);
                }

                isTemp     = true;
                isText     = true;
                isReadOnly = true;
                indexType  = Index.POINTER_INDEX;
                rowStore   = new RowStore();
                break;

            case TEXT_TABLE :
                if (!DatabaseURL.isFileBasedDatabaseType(db.getType())) {
                    throw Trace.error(Trace.DATABASE_IS_MEMORY_ONLY);
                }

                isText    = true;
                indexType = Index.POINTER_INDEX;
                rowStore  = new RowStore();
                break;

            case VIEW :
            case SYSTEM_VIEW :
                isView = true;
                break;
        }

        // type may have changed above for CACHED tables
        tableType       = type;
        tableName       = name;
        primaryKeyCols  = null;
        primaryKeyTypes = null;
        identityColumn  = -1;
        columnList      = new HashMappedList();
        indexList       = new Index[0];
        constraintList  = new Constraint[0];
        triggerLists    = new HsqlArrayList[TriggerDef.NUM_TRIGS];

// ----------------------------------------------------------------------------
// akede@users - 1.7.2 patch Files readonly
        // Changing the mode of the table if necessary
        if (db.isFilesReadOnly() && isFileBased()) {
            this.isReadOnly = true;
        }

// ----------------------------------------------------------------------------
    }

    boolean equals(Session session, String name) {

/*
        if (isTemp && (session != null
                       && session.getId() != ownerSessionId)) {
            return false;
        }
*/
        return (tableName.name.equals(name));
    }

    boolean equals(String name) {
        return (tableName.name.equals(name));
    }

    boolean equals(HsqlName name) {
        return (tableName.equals(name));
    }

    public final boolean isText() {
        return isText;
    }

    public final boolean isTemp() {
        return isTemp;
    }

    public final boolean isReadOnly() {
        return isReadOnly;
    }

    final boolean isView() {
        return isView;
    }

    final int getIndexType() {
        return indexType;
    }

    public final int getTableType() {
        return tableType;
    }

    public final boolean isDataReadOnly() {
        return isReadOnly;
    }

    /**
     * Used by INSERT, DELETE, UPDATE operations
     */
    void checkDataReadOnly() throws HsqlException {

        if (isReadOnly) {
            throw Trace.error(Trace.DATA_IS_READONLY);
        }
    }

// ----------------------------------------------------------------------------
// akede@users - 1.7.2 patch Files readonly
    void setDataReadOnly(boolean value) throws HsqlException {

        // Changing the Read-Only mode for the table is only allowed if the
        // the database can realize it.
        if (!value && database.isFilesReadOnly() && isFileBased()) {
            throw Trace.error(Trace.DATA_IS_READONLY);
        }

        isReadOnly = value;
    }

    /**
     * Text or Cached Tables are normally file based
     */
    boolean isFileBased() {
        return isCached || isText;
    }

    /**
     * For text tables
     */
    protected void setDataSource(Session s, String source, boolean isDesc,
                                 boolean newFile) throws HsqlException {
        throw (Trace.error(Trace.TABLE_NOT_FOUND));
    }

    /**
     * For text tables
     */
    protected String getDataSource() {
        return null;
    }

    /**
     * For text tables.
     */
    protected boolean isDescDataSource() {
        return false;
    }

    /**
     * For text tables.
     */
    public void setHeader(String header) throws HsqlException {
        throw Trace.error(Trace.TEXT_TABLE_HEADER);
    }

    /**
     * For text tables.
     */
    public String getHeader() {
        return null;
    }

    /**
     *  Adds a constraint.
     */
    void addConstraint(Constraint c) {

        constraintList =
            (Constraint[]) ArrayUtil.toAdjustedArray(constraintList, c,
                constraintList.length, 1);
    }

    /**
     *  Adds a constraint.
     */
    void addPKConstraint(Constraint c) {
        constraintList =
            (Constraint[]) ArrayUtil.toAdjustedArray(constraintList, c, 0, 1);
    }

    /**
     *  Returns the list of constraints.
     */
    Constraint[] getConstraints() {
        return constraintList;
    }

    /**
     *  Returns the primary constraint.
     */
    Constraint getPrimaryConstraint() {
        return primaryKeyCols.length == 0 ? null
                                          : constraintList[0];
    }

/** @todo fredt - this can be improved to ignore order of columns in
     * multi-column indexes */

    /**
     *  Returns the index supporting a constraint with the given column signature.
     *  Only Unique constraints are considered.
     */
    Index getUniqueConstraintIndexForColumns(int[] col) {

        if (ArrayUtil.areEqual(getPrimaryIndex().getColumns(), col,
                               col.length, true)) {