diff --git a/base/src/org/compiere/model/MTable.java b/base/src/org/compiere/model/MTable.java
index de1b93a6c8..acde802e0a 100644
--- a/base/src/org/compiere/model/MTable.java
+++ b/base/src/org/compiere/model/MTable.java
@@ -727,6 +727,17 @@ public class MTable extends X_AD_Table
 		}
 		return retValue;
 	}
+	
+	/**
+	 * Create query to retrieve one or more PO.
+	 * @param whereClause
+	 * @param trxName
+	 * @return Query
+	 */
+	public Query createQuery(String whereClause, String trxName) 
+	{
+		return new Query(this, whereClause, trxName);
+	}
 
 	/**
 	 * 	String Representation
diff --git a/base/src/org/compiere/model/POIterator.java b/base/src/org/compiere/model/POIterator.java
new file mode 100644
index 0000000000..b72e7ee711
--- /dev/null
+++ b/base/src/org/compiere/model/POIterator.java
@@ -0,0 +1,114 @@
+/*******************************************************************************
+ * Product: Adempiere ERP & CRM Smart Business Solution * Copyright (C)
+ * 1999-2006 Adempiere, Inc. All Rights Reserved. * This program is free
+ * software; you can redistribute it and/or modify it * under the terms version
+ * 2 of the GNU General Public License as published * by the Free Software
+ * Foundation. This program is distributed in the hope * that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied * warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General
+ * Public License for more details. * You should have received a copy of the GNU
+ * General Public License along * with this program; if not, write to the Free
+ * Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307 USA. *
+ * 
+ * Copyright (C) 2007 Low Heng Sin hengsin@avantz.com 
+ * Contributor(s): 
+ * __________________________________________
+ ******************************************************************************/
+package org.compiere.model;
+
+import java.util.Iterator;
+import java.util.List;
+
+import org.compiere.util.Env;
+
+/**
+ * 
+ * Iterator implementation to fetch PO one at a time using a prefetch ID list.
+ * @author Low Heng Sin
+ *
+ */
+public class POIterator implements Iterator<PO> {
+
+	private MTable table;
+	private List<Object[]> idList;
+	
+	private int iteratorIndex = -1;
+	private String trxName;
+	
+	private String keyWhereClause = null;
+
+	/**
+	 * @param table
+	 * @param idList
+	 * @param trxName
+	 */
+	public POIterator(MTable table, List<Object[]> idList, String trxName) {
+		this.table = table;
+		this.idList = idList;
+		this.trxName = trxName;
+	}
+
+	/**
+	 * @see java.util.Iterator#hasNext()
+	 */
+	public boolean hasNext() {
+		return ( iteratorIndex < (idList.size() - 1));
+	}
+
+	/**
+	 * @see java.util.Iterator#next()
+	 */
+	public PO next() {
+		if ( iteratorIndex < (idList.size() - 1)) {
+			iteratorIndex ++;
+			return get(iteratorIndex);
+		} else {
+			return null;
+		}
+	}
+
+	/**
+	 * not supported.
+	 */
+	public void remove() {
+		throw new UnsupportedOperationException("Remove operatiotn not supported.");
+	}
+	
+	/**
+	 * @return number of records
+	 */
+	public int size() {
+		return idList.size();
+	}
+	
+	/**
+	 * @param index
+	 * @return PO or null if index is invalid
+	 */
+	public PO get(int index) {
+		if (index <= (idList.size() - 1)) {
+			Object[] ids = idList.get(index);
+			if (ids.length == 1 && ids[0] instanceof Integer) {
+				return table.getPO((Integer)ids[0], trxName);
+			} else {
+				if (keyWhereClause == null) {
+					String[] keys = table.getKeyColumns();
+					POInfo info = POInfo.getPOInfo(Env.getCtx(), table.getAD_Table_ID());
+					if (info == null) return null;
+					StringBuffer sqlBuffer = info.buildSelect();
+					sqlBuffer.append(" WHERE ");
+					for (int i = 0; i < keys.length; i++) {
+						if (i > 0)
+							sqlBuffer.append(" AND ");
+						sqlBuffer.append(keys[i]).append(" = ? ");
+					}
+					keyWhereClause = sqlBuffer.toString();
+				}				
+				return table.getPO(keyWhereClause, ids, trxName);
+			}
+		} else {
+			return null;
+		}
+	}
+}
diff --git a/base/src/org/compiere/model/POResultSet.java b/base/src/org/compiere/model/POResultSet.java
new file mode 100644
index 0000000000..9cea15b059
--- /dev/null
+++ b/base/src/org/compiere/model/POResultSet.java
@@ -0,0 +1,78 @@
+/*******************************************************************************
+ * Product: Adempiere ERP & CRM Smart Business Solution * Copyright (C)
+ * 1999-2006 Adempiere, Inc. All Rights Reserved. * This program is free
+ * software; you can redistribute it and/or modify it * under the terms version
+ * 2 of the GNU General Public License as published * by the Free Software
+ * Foundation. This program is distributed in the hope * that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied * warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General
+ * Public License for more details. * You should have received a copy of the GNU
+ * General Public License along * with this program; if not, write to the Free
+ * Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307 USA. *
+ * 
+ * Copyright (C) 2007 Low Heng Sin hengsin@avantz.com 
+ * Contributor(s): 
+ * __________________________________________
+ ******************************************************************************/
+package org.compiere.model;
+
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+/**
+ * Simple wrapper over jdbc resultset
+ * @author Low Heng Sin
+ *
+ */
+public class POResultSet {
+
+	private String trxName;
+	private ResultSet resultSet;
+	private MTable table;
+	private PreparedStatement statement;
+
+	/**
+	 * 
+	 * @param table
+	 * @param ps
+	 * @param rs
+	 * @param trxName
+	 */
+	public POResultSet(MTable table, PreparedStatement ps, ResultSet rs, String trxName) {
+		this.table = table;
+		this.statement = ps;
+		this.resultSet = rs;
+		this.trxName = trxName;
+	}
+	
+	/**
+	 * 
+	 * @return PO or null if reach the end of resultset
+	 * @throws SQLException
+	 */
+	public PO next() throws SQLException {
+		if ( resultSet.next() ) {
+			return table.getPO(resultSet, trxName);
+		} else {
+			return null;
+		}
+	}
+	
+	/**
+	 * Release database resources.
+	 */
+	public void close() {
+		if (statement != null) {
+			try {
+				statement.close();
+			} catch (SQLException e) {
+			}
+		}
+		try {
+			resultSet.close();
+		} catch (SQLException e) {
+		}
+	}
+}
diff --git a/base/src/org/compiere/model/Query.java b/base/src/org/compiere/model/Query.java
new file mode 100644
index 0000000000..c508ffa118
--- /dev/null
+++ b/base/src/org/compiere/model/Query.java
@@ -0,0 +1,228 @@
+/*******************************************************************************
+ * Product: Adempiere ERP & CRM Smart Business Solution * Copyright (C)
+ * 1999-2006 Adempiere, Inc. All Rights Reserved. * This program is free
+ * software; you can redistribute it and/or modify it * under the terms version
+ * 2 of the GNU General Public License as published * by the Free Software
+ * Foundation. This program is distributed in the hope * that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied * warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General
+ * Public License for more details. * You should have received a copy of the GNU
+ * General Public License along * with this program; if not, write to the Free
+ * Software Foundation, Inc., * 59 Temple Place, Suite 330, Boston, MA
+ * 02111-1307 USA. *
+ * 
+ * Copyright (C) 2007 Low Heng Sin hengsin@avantz.com 
+ * Contributor(s): 
+ * __________________________________________
+ ******************************************************************************/
+package org.compiere.model;
+
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Iterator;
+import java.util.logging.Level;
+
+import org.compiere.util.CLogger;
+import org.compiere.util.DB;
+import org.compiere.util.Env;
+
+/**
+ * 
+ * @author Low Heng Sin
+ *
+ */
+public class Query {
+
+	private static CLogger log	= CLogger.getCLogger (Query.class);
+	
+	private MTable table = null;
+	private String whereClause = null;
+	private String orderBy = null;
+	private String trxName = null;
+	private Object[] parameters = null;
+	
+	/**
+	 * 
+	 * @param table
+	 * @param whereClause
+	 * @param trxName
+	 */
+	public Query(MTable table, String whereClause, String trxName) {
+		this.table = table;
+		this.whereClause = whereClause;
+		this.trxName = trxName;
+	}
+	
+	/**
+	 * Set query parameters
+	 * @param parameters
+	 */
+	public void setParameters(Object[] parameters) {
+		this.parameters = parameters;
+	}
+	
+	/**
+	 * Set order by clause ( without the order by sql keyword ).
+	 * @param orderBy
+	 */
+	public void setOrderBy(String orderBy) {
+		this.orderBy = orderBy;
+	}
+	
+	/**
+	 * Return a list of all po that match the query criteria.
+	 * @return List
+	 */
+	public List<PO> list() {
+		List<PO> list = new ArrayList<PO>();
+		
+		POInfo info = POInfo.getPOInfo(Env.getCtx(), table.getAD_Table_ID());
+		if (info == null) return null;
+		StringBuffer sqlBuffer = info.buildSelect();
+		if (whereClause != null && whereClause.trim().length() > 0)
+			sqlBuffer.append(" WHERE ").append(whereClause);
+		if (orderBy != null && orderBy.trim().length() > 0)
+			sqlBuffer.append(" Order By ").append(orderBy);
+		String sql = sqlBuffer.toString();
+		
+		PreparedStatement pstmt = null;
+		try
+		{
+			pstmt = DB.prepareStatement (sql, trxName);
+			if (parameters != null && parameters.length > 0) 
+			{
+				for (int i = 0; i < parameters.length; i++)
+				{
+					pstmt.setObject(i+1, parameters[i]);
+				}
+			}
+			ResultSet rs = pstmt.executeQuery ();
+			while (rs.next ())
+			{
+				PO po = table.getPO(rs, trxName);
+				list.add(po);
+			}
+			rs.close ();
+			pstmt.close ();
+			pstmt = null;
+		}
+		catch (Exception e)
+		{
+			log.log(Level.SEVERE, sql, e);
+			log.saveError("Error", e);
+		}
+		try
+		{
+			if (pstmt != null)
+				pstmt.close ();
+			pstmt = null;
+		}
+		catch (Exception e)
+		{
+			pstmt = null;
+		}
+		return list;
+	}
+	
+	/**
+	 * Return an Iterator implementation to fetch one PO at a time. The implementation first retrieve
+	 * all IDS that match the query criteria and issue sql query to fetch the PO when caller want to
+	 * fetch the next PO. This minimize memory usage but it is slower than the list method.
+	 * @return Iterator
+	 */
+	public Iterator iterate() {
+		String[] keys = table.get_KeyColumns();
+		StringBuffer sqlBuffer = new StringBuffer(" SELECT ");
+		for (int i = 0; i < keys.length; i++) {
+			if (i > 0)
+				sqlBuffer.append(", ");
+			sqlBuffer.append(keys[i]);
+		}
+		sqlBuffer.append(" FROM ").append(table.get_TableName());
+		if (whereClause != null && whereClause.trim().length() > 0)
+			sqlBuffer.append(" WHERE ").append(whereClause);
+		if (orderBy != null && orderBy.trim().length() > 0)
+			sqlBuffer.append(" Order By ").append(orderBy);
+		String sql = sqlBuffer.toString();		
+		PreparedStatement pstmt = null;
+		List<Object[]> idList = new ArrayList<Object[]>();
+		try
+		{
+			pstmt = DB.prepareStatement (sql, trxName);
+			if (parameters != null && parameters.length > 0) 
+			{
+				for (int i = 0; i < parameters.length; i++)
+				{
+					pstmt.setObject(i+1, parameters[i]);
+				}
+			}
+			ResultSet rs = pstmt.executeQuery ();
+			while (rs.next ())
+			{
+				Object[] ids = new Object[keys.length];
+				for (int i = 0; i < ids.length; i++) {
+					ids[i] = rs.getObject(i+1);
+				}
+				idList.add(ids);
+			}
+			rs.close ();
+			pstmt.close ();
+			pstmt = null;
+		}
+		catch (Exception e)
+		{
+			log.log(Level.SEVERE, sql, e);
+			log.saveError("Error", e);
+		}
+		try
+		{
+			if (pstmt != null)
+				pstmt.close ();
+			pstmt = null;
+		}
+		catch (Exception e)
+		{
+			pstmt = null;
+		}
+		return new POIterator(table, idList, trxName);
+	}
+	
+	/**
+	 * Return a simple wrapper over a jdbc resultset. It is the caller responsibility to
+	 * call the close method to release the underlying database resources.
+	 * @return POResultSet
+	 */
+	public POResultSet scroll() {
+		POInfo info = POInfo.getPOInfo(Env.getCtx(), table.getAD_Table_ID());
+		if (info == null) return null;
+		StringBuffer sqlBuffer = info.buildSelect();
+		if (whereClause != null && whereClause.trim().length() > 0)
+			sqlBuffer.append(" WHERE ").append(whereClause);
+		if (orderBy != null && orderBy.trim().length() > 0)
+			sqlBuffer.append(" Order By ").append(orderBy);
+		String sql = sqlBuffer.toString();
+		
+		PreparedStatement pstmt = null;
+		try
+		{
+			pstmt = DB.prepareStatement (sql, trxName);
+			if (parameters != null && parameters.length > 0) 
+			{
+				for (int i = 0; i < parameters.length; i++)
+				{
+					pstmt.setObject(i+1, parameters[i]);
+				}
+			}
+			ResultSet rs = pstmt.executeQuery ();
+			return new POResultSet(table, pstmt, rs, trxName);
+		}
+		catch (Exception e)
+		{
+			log.log(Level.SEVERE, sql, e);
+			log.saveError("Error", e);
+		}
+		return null;
+	}
+}