Quadcap Embeddable Database

com/quadcap/sql/meta/MetaCrossReference.java

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package com.quadcap.sql.meta;

/* 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.IOException;

import java.util.Iterator;

import java.sql.DatabaseMetaData;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;

import com.quadcap.sql.Column;
import com.quadcap.sql.Constraint;
import com.quadcap.sql.Database;
import com.quadcap.sql.Expression;
import com.quadcap.sql.ImportedKeyConstraint;
import com.quadcap.sql.Relation;
import com.quadcap.sql.Row;
import com.quadcap.sql.Session;
import com.quadcap.sql.StaticCursor;
import com.quadcap.sql.Table;

import com.quadcap.sql.index.BCursor;
import com.quadcap.sql.index.Btree;

import com.quadcap.sql.types.*;

import com.quadcap.util.Debug;

/**
 * A Cursor supporting the <code>getCrossReference</code>,
 * <code>getExportedKeys</code>, <code>getImportedKeys</code>
 * functions.
 *
 * @author Stan Bailes
 */
public class MetaCrossReference extends MetaCursor {
    static Column[] cols = {
        new Column("PKTABLE_CAT", typeString),          // 1
        new Column("PKTABLE_SCHEM", typeString),        // 2 
        new Column("PKTABLE_NAME", typeString),         // 3
        new Column("PKCOLUMN_NAME", typeString),        // 4
        new Column("FKTABLE_CAT", typeString),          // 5
        new Column("FKTABLE_SCHEM", typeString),        // 6 
        new Column("FKTABLE_NAME", typeString),         // 7
        new Column("FKCOLUMN_NAME", typeString),        // 8
        new Column("KEY_SEQ", typeShort),               // 9
        new Column("UPDATE_RULE", typeShort),           // 10
        new Column("DELETE_RULE", typeShort),           // 11
        new Column("FK_NAME", typeString),              // 12
        new Column("PK_NAME", typeString),              // 13
        new Column("DEFERRABILITY", typeShort)          // 14
    };

    static int[] sortColumns = { 1, 2, 3, 9 };

    public MetaCrossReference(Session session, Expression predicate)
        throws SQLException
    {
        super(session, predicate);
        try {
            addColumns(cols);
            Database db = session.getDatabase();
            session.getTableWriteLock("#Schema");
            synchronized (db.getFile().getLock()) {
                Iterator iter = db.getRelationNameIterator();
                while (iter.hasNext()) {
                    String name = (String)iter.next();
                    Relation r = db.getRelation(name);
                    if (r instanceof Table) {
                        Table t = (Table)r;
                        int num = t.getNumConstraints();
                        for (int i = 0; i < num; i++) {
                            Constraint c = t.getConstraint(i);
                            if (c instanceof ImportedKeyConstraint) {
                                doConstraint(t, (ImportedKeyConstraint)c);
                            }
                        }
                    }
                }
            }
            sort();
        } catch (ValueException e) {
            Debug.print(e);
            SQLException te = new SQLException(e.toString(), "Q000L");
            te.setNextException(e);
            throw te;
        } catch (IOException e) {
            Debug.print(e);
            throw new SQLException(e.toString(), "Q000M");
        }           
    }

    public int[] getSortColumns() {
        return sortColumns;
    }

    void doConstraint(Table t, ImportedKeyConstraint c)
        throws SQLException, IOException
    {
        int[] colIndices = c.getColumns();
        int[] fCols = c.getFCols(session.getDatabase());
        Table f = c.getFTable(session.getDatabase());
        for (int i = 0; i < colIndices.length; i++) {
            Column col = t.getColumn(colIndices[i]);
            Column fcol = f.getColumn(fCols[i]);
            Row row = doColumn(t, f, c, i, col, fcol);
            if (rowMatch(row)) {
                addRow(row);
            }
        }
    }

    Row doColumn(Table t, Table f, ImportedKeyConstraint c, int pos, Column col,
                 Column fcol)
        throws SQLException
    {
        Row row = new Row(14);
        row.set(1, ValueNull.valueNull);
        doTableName(2, row, f.getName());
        row.set(4, new ValueString(fcol.getShortName()));
        
        row.set(5, ValueNull.valueNull);
        doTableName(6, row, t.getName());
        row.set(8, new ValueString(col.getShortName()));
        
        row.set(9, new ValueInteger(pos+1));

        int spec = c.getSpec();
        int ud = DatabaseMetaData.importedKeyRestrict;
        if ((spec & Constraint.CASCADE) != 0) {
            ud = DatabaseMetaData.importedKeyCascade;
        }
        ValueInteger v = new ValueInteger(ud);
        row.set(10, v);
        row.set(11, v);

        row.set(12, new ValueString(c.getName()));
        row.set(13, ValueNull.valueNull);

        ud = DatabaseMetaData.importedKeyNotDeferrable;
        if ((spec & Constraint.DEFERRABLE) != 0) {
            if ((spec & Constraint.INIT_DEFERRED) != 0) {
                ud = DatabaseMetaData.importedKeyInitiallyDeferred;
            } else {
                ud = DatabaseMetaData.importedKeyInitiallyImmediate;
            }
        }
        row.set(14, new ValueInteger(ud));
        return row;
    }     
}