insertsqlbuilder.java

把java对象映射成数据库表中的一条记录

/*
 *
 * The contents of this file are subject to the Mozilla Public License
 * Version 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the
 * License for the specific language governing rights and limitations under
 * the License.
 *
 * The Original Code is jRelationalFramework.
 *
 * The Initial Developer of the Original Code is is.com.
 * Portions created by is.com are Copyright (C) 2000 is.com.
 * All Rights Reserved.
 *
 * Contributor(s): Jonathan Carlson ([e-mail])
 * Contributor(s): ____________________________________
 *
 * Alternatively, the contents of this file may be used under the terms of
 * the GNU General Public License (the "GPL") or the GNU Lesser General
 * Public license (the "LGPL"), in which case the provisions of the GPL or
 * LGPL are applicable instead of those above.  If you wish to allow use of
 * your version of this file only under the terms of either the GPL or LGPL
 * and not to allow others to use your version of this file under the MPL,
 * indicate your decision by deleting the provisions above and replace them
 * with the notice and other provisions required by either the GPL or LGPL
 * License.  If you do not delete the provisions above, a recipient may use
 * your version of this file under either the MPL or GPL or LGPL License.
 *
 */
package com.is.jrf;


import com.is.util.sql.JDBCHelper;

import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;


/**
 *  Instances of this class build SQL to do INSERT statements.
 */
public class InsertSQLBuilder
        extends SQLBuilder
  {

  /* ===============  Constructors  =============== */

  /**
   * This constructor throws an exception.
   */
  public InsertSQLBuilder()
    {
    super();
    }

  public InsertSQLBuilder(AbstractDomain domain)
    {
    super(domain);
    }


  /**
   * Build SQL to insert a row using the columnSpecs and the next
   * available primary key object ID.
   *
   * @param aPO a value of type 'PersistentObject'
   * @param pkId a value of type 'Object' that will be the primary key
   * @return a value of type 'String'
   */
  public String buildSQL(PersistentObject aPO,
                         JDBCHelper aJDBCHelper,
                         String tableName,
                         List columnSpecs)
    {
    if (i_dbPolicy == null)
        {
        throw new DatabaseException(
            "The DatabasePolicy has not been set for " + this);
        }

    StringBuffer sqlBuffer = new StringBuffer();
    sqlBuffer
            .append(" INSERT INTO ")
            .append(tableName)
            .append(" (");
    Iterator iterator = columnSpecs.iterator();
    ColumnSpec aColumnSpec = null;
    while (iterator.hasNext())
        {
        aColumnSpec = (ColumnSpec)iterator.next();
        sqlBuffer.append(aColumnSpec.getColumnName());
        if (iterator.hasNext())
            {
            sqlBuffer.append(", ");
            }
        }
    sqlBuffer.append(") VALUES (");

    iterator = columnSpecs.iterator();
    while (iterator.hasNext())
        {
        aColumnSpec = (ColumnSpec)iterator.next();
        if (aColumnSpec.isSequencedPrimaryKey() &&
            i_dbPolicy.autoIncrementIdentifier() == null &&
            aColumnSpec.getValueFrom(aPO) == null)
            {
            Long pk = i_domain.nextSequence(aJDBCHelper);
            aColumnSpec.setValueTo(pk, aPO);
            sqlBuffer.append(pk);
            }
        else
            {
            String sqlValue = aColumnSpec.getSqlValueFrom(aPO, i_dbPolicy);
            sqlBuffer.append(sqlValue);
            }
        if (iterator.hasNext())
            {
            sqlBuffer.append(", ");
            }
        }
    sqlBuffer.append(")");
    return sqlBuffer.toString();
    } // buildSQL(PersistentObject, aJDBCHelper, tableName, columnSpecs)


  } // InsertSQLBuilder