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Cayenne Object Persistence Framework including all dependencies.
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/* ====================================================================
 * 
 * The ObjectStyle Group Software License, version 1.1
 * ObjectStyle Group - http://objectstyle.org/
 * 
 * Copyright (c) 2002-2005, Andrei (Andrus) Adamchik and individual authors
 * of the software. All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 
 * 2. 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.
 * 
 * 3. The end-user documentation included with the redistribution, if any,
 *    must include the following acknowlegement:
 *    "This product includes software developed by independent contributors
 *    and hosted on ObjectStyle Group web site (http://objectstyle.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 * 
 * 4. The names "ObjectStyle Group" and "Cayenne" must not be used to endorse
 *    or promote products derived from this software without prior written
 *    permission. For written permission, email
 *    "andrus at objectstyle dot org".
 * 
 * 5. Products derived from this software may not be called "ObjectStyle"
 *    or "Cayenne", nor may "ObjectStyle" or "Cayenne" appear in their
 *    names without prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 OBJECTSTYLE GROUP OR
 * ITS 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 and hosted on ObjectStyle Group web site.  For more
 * information on the ObjectStyle Group, please see
 * .
 */
package org.objectstyle.cayenne.access.trans;

import java.util.Iterator;
import java.util.Map;

import org.objectstyle.cayenne.CayenneRuntimeException;
import org.objectstyle.cayenne.map.DbAttribute;
import org.objectstyle.cayenne.map.DbEntity;
import org.objectstyle.cayenne.map.DbRelationship;
import org.objectstyle.cayenne.query.UpdateQuery;

/** Class implements default translation mechanism of 
  * org.objectstyle.cayenne.query.UpdateQuery
  * objects to SQL UPDATE statements.
  *
  * @author Andrei Adamchik
  */
public class UpdateTranslator extends QueryAssembler {

    public String aliasForTable(DbEntity dbEnt) {
        throw new RuntimeException("aliases not supported");
    }

    public void dbRelationshipAdded(DbRelationship dbRel) {
        throw new RuntimeException("db relationships not supported");
    }

    /** Method that converts an update query into SQL string */
    public String createSqlString() throws Exception {
        StringBuffer queryBuf = new StringBuffer();
        queryBuf.append("UPDATE ");

        // 1. append table name
        DbEntity dbEnt = getRootEntity().getDbEntity();
        queryBuf.append(dbEnt.getFullyQualifiedName());

        // 2. build "set ..." clause
        buildSetClause(queryBuf, (UpdateQuery) query);

        // 3. build qualifier
        String qualifierStr =
            adapter.getQualifierTranslator(this).doTranslation();
        if (qualifierStr != null)
            queryBuf.append(" WHERE ").append(qualifierStr);

        return queryBuf.toString();
    }

    /** Translate updated values and relationships into
     *  "SET ATTR1 = Val1, ..." SQL statement.
     */
    private void buildSetClause(StringBuffer queryBuf, UpdateQuery query) {
        Map updAttrs = query.getUpdAttributes();
        // set of keys.. each key is supposed to be ObjAttribute
        Iterator attrIt = updAttrs.entrySet().iterator();

        if (!attrIt.hasNext())
            throw new CayenneRuntimeException("Nothing to update.");

        DbEntity dbEnt = getRootEntity().getDbEntity();
        queryBuf.append(" SET ");

        // append updated attribute values
        boolean appendedSomething = false;

        // now process other attrs in the loop
        while (attrIt.hasNext()) {
        	Map.Entry entry = (Map.Entry) attrIt.next();
            String nextKey = (String) entry.getKey();
            Object attrVal = entry.getValue();

            if (appendedSomething)
                queryBuf.append(", ");

            queryBuf.append(nextKey).append(" = ?");
            super.addToParamList(
                (DbAttribute) dbEnt.getAttribute(nextKey),
                attrVal);
            appendedSomething = true;
        }
    }
}