package org.apache.ojb.broker.accesslayer.sql;

 /* Copyright 2002-2005 The Apache Software Foundation

  *

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  *     http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  */

 import org.apache.ojb.broker.metadata.ClassDescriptor;

 import org.apache.ojb.broker.metadata.FieldDescriptor;

 import org.apache.ojb.broker.util.logging.Logger;

 /**

  * Model an UPDATE Statement

  *

  * @author <a href="mailto:jbraeuchi@hotmail.com">Jakob Braeuchi</a>

  * @version $Id: SqlUpdateStatement.java,v 1.1 2007-08-24 22:17:39 ewestfal Exp $

  */

 public class SqlUpdateStatement extends SqlPkStatement

 {

     protected String sql;

     /**

      * Constructor for SqlUpdateStatement.

      *

      * @param cld

      * @param logger

      */

     public SqlUpdateStatement(ClassDescriptor cld, Logger logger)

     {

         super(cld, logger);

     }

     /**

      * generates a SET-phrase for a prepared update statement.

      *

      * @param stmt the StringBuffer

      */

     private void appendSetClause(ClassDescriptor cld, StringBuffer stmt)

     {

         FieldDescriptor[] fields = cld.getNonPkRwFields();

         if(fields.length == 0)

         {

             return;

         }

         stmt.append(" SET ");

         for(int i = 0; i < fields.length; i++)

         {

             stmt.append(fields[i].getColumnName());

             stmt.append("=?");

             if(i < fields.length - 1)

             {

                 stmt.append(",");

             }

         }

     }

     /**

      * @see SqlStatement#getStatement()

      */

     public String getStatement()

     {

         if(sql == null)

         {

             StringBuffer stmt = new StringBuffer(1024);

             ClassDescriptor cld = getClassDescriptor();

             stmt.append("UPDATE ");

             appendTable(cld, stmt);

             appendSetClause(cld, stmt);

             appendWhereClause(cld, true, stmt); //use Locking

             sql = stmt.toString();

         }

         return sql;

     }

 }