0.10/catalog/src/main/java/org/apache/oodt/cas/catalog/struct/impl/index/WorkflowManagerDataSourceIndex.java - oodt - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one or more
  * contributor license agreements.  See the NOTICE file distributed with
  * this work for additional information regarding copyright ownership.
  * The ASF licenses this file to You 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.
  */
 package org.apache.oodt.cas.catalog.struct.impl.index;

 //JDK imports
 import java.io.UnsupportedEncodingException;
 import java.net.URLDecoder;
 import java.net.URLEncoder;
 import java.sql.Connection;
 import java.sql.ResultSet;
 import java.sql.Statement;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Properties;
 import java.util.Vector;
 import java.util.logging.Level;
 import java.util.logging.Logger;

 //SQL imports
 import javax.sql.DataSource;

 //OODT imports
 import org.apache.oodt.cas.catalog.exception.CatalogIndexException;
 import org.apache.oodt.cas.catalog.exception.QueryServiceException;
 import org.apache.oodt.cas.catalog.page.IndexPager;
 import org.apache.oodt.cas.catalog.page.IngestReceipt;
 import org.apache.oodt.cas.catalog.query.ComparisonQueryExpression;
 import org.apache.oodt.cas.catalog.query.NotQueryExpression;
 import org.apache.oodt.cas.catalog.query.QueryExpression;
 import org.apache.oodt.cas.catalog.query.QueryLogicalGroup;
 import org.apache.oodt.cas.catalog.query.StdQueryExpression;
 import org.apache.oodt.cas.catalog.struct.Index;
 import org.apache.oodt.cas.catalog.struct.QueryService;
 import org.apache.oodt.cas.catalog.struct.TransactionId;
 import org.apache.oodt.cas.catalog.struct.TransactionIdFactory;
 import org.apache.oodt.cas.catalog.struct.impl.transaction.LongTransactionIdFactory;
 import org.apache.oodt.cas.catalog.term.Term;
 import org.apache.oodt.cas.catalog.term.TermBucket;
 import org.apache.oodt.commons.database.DatabaseConnectionBuilder;

 //EDA imports
 import org.apache.oodt.commons.util.DateConvert;

 /**
  * @author bfoster
  * @version $Revision$
  *
  * <p>
  * A queriable index for querying for original cas-workflow instance metadata (not for cas-workflow2)
  * <p>
  */
 public class WorkflowManagerDataSourceIndex implements Index, QueryService {

 	private static final Logger LOG = Logger.getLogger(WorkflowManagerDataSourceIndex.class.getName());

 	protected DataSource dataSource;

 	public WorkflowManagerDataSourceIndex(String user, String pass, String driver, String jdbcUrl) throws InstantiationException {
 		this.dataSource = DatabaseConnectionBuilder.buildDataSource(user, pass, driver, jdbcUrl);
 	}

 	public List<TransactionId<?>> getPage(IndexPager indexPage)
 			throws CatalogIndexException {
 		// TODO Auto-generated method stub
 		return null;
 	}

 	public Properties getProperties() throws CatalogIndexException {
 		return new Properties();
 	}

 	public String getProperty(String key) throws CatalogIndexException {
 		return null;
 	}

 	public TransactionIdFactory getTransactionIdFactory() throws CatalogIndexException {
 		return new LongTransactionIdFactory();
 	}

 	public boolean hasTransactionId(TransactionId<?> transactionId)
 			throws CatalogIndexException {
 		Connection conn = null;
 		Statement stmt = null;
 		ResultSet rs = null;
 		try {
 			conn = this.dataSource.getConnection();
 			stmt = conn.createStatement();
 			rs = stmt.executeQuery("SELECT DISTINCT workflow_instance_id FROM workflow_instance_metadata WHERE workflow_instance_id = '" + transactionId + "'");
 			return rs.next();
 		}catch (Exception e) {
 			throw new CatalogIndexException("Failed to check for workflow id '" + transactionId + "' : " + e.getMessage(), e);
 		}finally {
 			try {
 				conn.close();
 			}catch(Exception e) {}
 			try {
 				stmt.close();
 			}catch(Exception e) {}
 			try {
 				rs.close();
 			}catch(Exception e) {}
 		}
 	}

 	public List<TermBucket> getBuckets(TransactionId<?> transactionId)
 			throws QueryServiceException {
 		Connection conn = null;
 		Statement stmt = null;
 		ResultSet rs = null;
 		try {
 			conn = this.dataSource.getConnection();
 			stmt = conn.createStatement();
 			rs = stmt.executeQuery("SELECT * FROM workflow_instance_metadata WHERE workflow_instance_id = '" + transactionId + "'");

 			TermBucket tb = new TermBucket("Workflows");
 			while (rs.next()) {
                 String key = rs.getString("workflow_met_key");
                 String value = URLDecoder.decode(rs.getString("workflow_met_val"), "UTF-8");
                 tb.addTerm(new Term(key, Collections.singletonList(value)));
             }
 			return Collections.singletonList(tb);
 		}catch (Exception e) {
 			throw new QueryServiceException("Failed to get Workflow Instance Metadata for workflow id '" + transactionId + "' : " + e.getMessage(), e);
 		}finally {
 			try {
 				conn.close();
 			}catch(Exception e) {}
 			try {
 				stmt.close();
 			}catch(Exception e) {}
 			try {
 				rs.close();
 			}catch(Exception e) {}
 		}
 	}

 	public Map<TransactionId<?>, List<TermBucket>> getBuckets(
 			List<TransactionId<?>> transactionIds) throws QueryServiceException {
 		Map<TransactionId<?>, List<TermBucket>> returnMap = new HashMap<TransactionId<?>, List<TermBucket>>();
 		for (TransactionId<?> transactionId : transactionIds)
 			returnMap.put(transactionId, this.getBuckets(transactionId));
 		return returnMap;
 	}

 	public List<IngestReceipt> query(QueryExpression queryExpression)
 			throws QueryServiceException {
 		Connection conn = null;
 		Statement stmt = null;
 		ResultSet rs = null;
 		try {
 			conn = this.dataSource.getConnection();
 			stmt = conn.createStatement();
 			String sqlQuery = "SELECT workflow_instance_id,start_date_time FROM workflow_instances WHERE workflow_instance_id IN (" + this.getSqlQuery(queryExpression) + ")";
 	        LOG.log(Level.INFO, "Performing Query: " + sqlQuery);
 			rs = stmt.executeQuery(sqlQuery);

 			List<IngestReceipt> receipts = new Vector<IngestReceipt>();
 			while (rs.next())
                 receipts.add(new IngestReceipt(new LongTransactionIdFactory().createTransactionId(rs.getString("workflow_instance_id")), DateConvert.isoParse(rs.getString("start_date_time"))));
 			return receipts;
 		}catch (Exception e) {
 			throw new QueryServiceException("Failed to query Workflow Instances Database : " + e.getMessage(), e);
 		}finally {
 			try {
 				conn.close();
 			}catch(Exception e) {}
 			try {
 				stmt.close();
 			}catch(Exception e) {}
 			try {
 				rs.close();
 			}catch(Exception e) {}
 		}
 	}

 	public List<IngestReceipt> query(QueryExpression queryExpression, int startIndex, int endIndex) throws QueryServiceException {
 		Connection conn = null;
 		Statement stmt = null;
 		ResultSet rs = null;
 		try {
 			conn = this.dataSource.getConnection();
 			stmt = conn.createStatement();
 			String sqlQuery = "SELECT workflow_instance_id,start_date_time FROM workflow_instances WHERE workflow_instance_id IN (" + this.getSqlQuery(queryExpression) + ")";
 	        LOG.log(Level.INFO, "Performing Query: " + sqlQuery);
 			rs = stmt.executeQuery(sqlQuery);

 			List<IngestReceipt> receipts = new Vector<IngestReceipt>();
 			int index = 0;
 			while (startIndex > index && rs.next()) index++;
 			while (rs.next() && index++ <= endIndex)
 				receipts.add(new IngestReceipt(new LongTransactionIdFactory().createTransactionId(rs.getString("workflow_instance_id")), DateConvert.isoParse(rs.getString("start_date_time"))));
 			return receipts;
 		}catch (Exception e) {
 			throw new QueryServiceException("Failed to query Workflow Instances Database : " + e.getMessage(), e);
 		}finally {
 			try {
 				conn.close();
 			}catch(Exception e) {}
 			try {
 				stmt.close();
 			}catch(Exception e) {}
 			try {
 				rs.close();
 			}catch(Exception e) {}
 		}
 	}

 	public int sizeOf(QueryExpression queryExpression)
 			throws QueryServiceException {
 		Connection conn = null;
 		Statement stmt = null;
 		ResultSet rs = null;
 		try {
 			conn = this.dataSource.getConnection();
 			stmt = conn.createStatement();
 			String sqlQuery = "SELECT COUNT(workflow_instance_id) AS numInstances FROM workflow_instances WHERE workflow_instance_id IN (" + this.getSqlQuery(queryExpression) + ")";
 			LOG.log(Level.INFO, "Performing Query: " + sqlQuery);
 			rs = stmt.executeQuery(sqlQuery);

 			int numInstances = 0;
 			while (rs.next())
 				numInstances = rs.getInt("numInstances");

 			return numInstances;
 		} catch (Exception e) {
 			throw new QueryServiceException(
 					"Failed to get size of query in Workflow Instances Database : "
 							+ e.getMessage(), e);
 		} finally {
 			try {
 				conn.close();
 			} catch (Exception e) {
 			}
 			try {
 				stmt.close();
 			} catch (Exception e) {
 			}
 			try {
 				rs.close();
 			} catch (Exception e) {
 			}
 		}
 	}

     private String getSqlQuery(QueryExpression queryExpression) throws QueryServiceException, UnsupportedEncodingException {
         String sqlQuery = null;
         if (queryExpression instanceof QueryLogicalGroup) {
         	QueryLogicalGroup qlg = (QueryLogicalGroup) queryExpression;
             sqlQuery = "(" + this.getSqlQuery(qlg.getExpressions().get(0));
             String op = qlg.getOperator() == QueryLogicalGroup.Operator.AND ? "INTERSECT" : "UNION";
             for (int i = 1; i < qlg.getExpressions().size(); i++)
                 sqlQuery += ") " + op + " (" + this.getSqlQuery(qlg.getExpressions().get(i));
             sqlQuery += ")";
         }else if (queryExpression instanceof ComparisonQueryExpression){
         	ComparisonQueryExpression cqe = (ComparisonQueryExpression) queryExpression;
         	String operator = null;
             if (cqe.getOperator().equals(ComparisonQueryExpression.Operator.EQUAL_TO)) {
             	operator = "=";
             } else if (cqe.getOperator().equals(ComparisonQueryExpression.Operator.GREATER_THAN)) {
             	operator = ">";
             } else if (cqe.getOperator().equals(ComparisonQueryExpression.Operator.GREATER_THAN_EQUAL_TO)) {
             	operator = ">=";
             } else if (cqe.getOperator().equals(ComparisonQueryExpression.Operator.LESS_THAN)) {
             	operator = "<";
             } else if (cqe.getOperator().equals(ComparisonQueryExpression.Operator.LESS_THAN_EQUAL_TO)) {
             	operator = "<=";
             } else {
                 throw new QueryServiceException("Invalid ComparisonQueryExpression Operator '" + cqe.getOperator() + "'");
             }

             sqlQuery = "SELECT DISTINCT workflow_instance_id FROM workflow_instance_metadata WHERE workflow_met_key = '" + cqe.getTerm().getName() + "' AND (";
         	for (int i = 0; i < cqe.getTerm().getValues().size(); i++) {
         		String value = cqe.getTerm().getValues().get(i);
                 sqlQuery += "workflow_met_val " + operator + " '" + URLEncoder.encode(value, "UTF-8") + "'";
 	            if ((i + 1) < cqe.getTerm().getValues().size())
 	            	sqlQuery += "OR";
         	}
         	sqlQuery += ")";
         }else if (queryExpression instanceof NotQueryExpression) {
         	NotQueryExpression nqe = (NotQueryExpression) queryExpression;
             sqlQuery = "SELECT DISTINCT workflow_instance_id FROM workflow_instance_metadata WHERE NOT (" + this.getSqlQuery(nqe.getQueryExpression()) + ")";
         }else if (queryExpression instanceof StdQueryExpression) {
             sqlQuery = "SELECT DISTINCT workflow_instance_id FROM workflow_instance_metadata";
         }else {
             throw new QueryServiceException("Invalid QueryExpression '" + queryExpression.getClass().getCanonicalName() + "'");
         }
         return sqlQuery;
     }

 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You 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.
	*/
	package org.apache.oodt.cas.catalog.struct.impl.index;

	//JDK imports
	import java.io.UnsupportedEncodingException;
	import java.net.URLDecoder;
	import java.net.URLEncoder;
	import java.sql.Connection;
	import java.sql.ResultSet;
	import java.sql.Statement;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.List;
	import java.util.Map;
	import java.util.Properties;
	import java.util.Vector;
	import java.util.logging.Level;
	import java.util.logging.Logger;

	//SQL imports
	import javax.sql.DataSource;

	//OODT imports
	import org.apache.oodt.cas.catalog.exception.CatalogIndexException;
	import org.apache.oodt.cas.catalog.exception.QueryServiceException;
	import org.apache.oodt.cas.catalog.page.IndexPager;
	import org.apache.oodt.cas.catalog.page.IngestReceipt;
	import org.apache.oodt.cas.catalog.query.ComparisonQueryExpression;
	import org.apache.oodt.cas.catalog.query.NotQueryExpression;
	import org.apache.oodt.cas.catalog.query.QueryExpression;
	import org.apache.oodt.cas.catalog.query.QueryLogicalGroup;
	import org.apache.oodt.cas.catalog.query.StdQueryExpression;
	import org.apache.oodt.cas.catalog.struct.Index;
	import org.apache.oodt.cas.catalog.struct.QueryService;
	import org.apache.oodt.cas.catalog.struct.TransactionId;
	import org.apache.oodt.cas.catalog.struct.TransactionIdFactory;
	import org.apache.oodt.cas.catalog.struct.impl.transaction.LongTransactionIdFactory;
	import org.apache.oodt.cas.catalog.term.Term;
	import org.apache.oodt.cas.catalog.term.TermBucket;
	import org.apache.oodt.commons.database.DatabaseConnectionBuilder;

	//EDA imports
	import org.apache.oodt.commons.util.DateConvert;

	/**
	* @author bfoster
	* @version $Revision$
	*
	* <p>
	* A queriable index for querying for original cas-workflow instance metadata (not for cas-workflow2)
	* <p>
	*/
	public class WorkflowManagerDataSourceIndex implements Index, QueryService {

	private static final Logger LOG = Logger.getLogger(WorkflowManagerDataSourceIndex.class.getName());

	protected DataSource dataSource;

	public WorkflowManagerDataSourceIndex(String user, String pass, String driver, String jdbcUrl) throws InstantiationException {
	this.dataSource = DatabaseConnectionBuilder.buildDataSource(user, pass, driver, jdbcUrl);
	}

	public List<TransactionId<?>> getPage(IndexPager indexPage)
	throws CatalogIndexException {
	// TODO Auto-generated method stub
	return null;
	}

	public Properties getProperties() throws CatalogIndexException {
	return new Properties();
	}

	public String getProperty(String key) throws CatalogIndexException {
	return null;
	}

	public TransactionIdFactory getTransactionIdFactory() throws CatalogIndexException {
	return new LongTransactionIdFactory();
	}

	public boolean hasTransactionId(TransactionId<?> transactionId)
	throws CatalogIndexException {
	Connection conn = null;
	Statement stmt = null;
	ResultSet rs = null;
	try {
	conn = this.dataSource.getConnection();
	stmt = conn.createStatement();
	rs = stmt.executeQuery("SELECT DISTINCT workflow_instance_id FROM workflow_instance_metadata WHERE workflow_instance_id = '" + transactionId + "'");
	return rs.next();
	}catch (Exception e) {
	throw new CatalogIndexException("Failed to check for workflow id '" + transactionId + "' : " + e.getMessage(), e);
	}finally {
	try {
	conn.close();
	}catch(Exception e) {}
	try {
	stmt.close();
	}catch(Exception e) {}
	try {
	rs.close();
	}catch(Exception e) {}
	}
	}

	public List<TermBucket> getBuckets(TransactionId<?> transactionId)
	throws QueryServiceException {
	Connection conn = null;
	Statement stmt = null;
	ResultSet rs = null;
	try {
	conn = this.dataSource.getConnection();
	stmt = conn.createStatement();
	rs = stmt.executeQuery("SELECT * FROM workflow_instance_metadata WHERE workflow_instance_id = '" + transactionId + "'");

	TermBucket tb = new TermBucket("Workflows");
	while (rs.next()) {
	String key = rs.getString("workflow_met_key");
	String value = URLDecoder.decode(rs.getString("workflow_met_val"), "UTF-8");
	tb.addTerm(new Term(key, Collections.singletonList(value)));
	}
	return Collections.singletonList(tb);
	}catch (Exception e) {
	throw new QueryServiceException("Failed to get Workflow Instance Metadata for workflow id '" + transactionId + "' : " + e.getMessage(), e);
	}finally {
	try {
	conn.close();
	}catch(Exception e) {}
	try {
	stmt.close();
	}catch(Exception e) {}
	try {
	rs.close();
	}catch(Exception e) {}
	}
	}

	public Map<TransactionId<?>, List<TermBucket>> getBuckets(
	List<TransactionId<?>> transactionIds) throws QueryServiceException {
	Map<TransactionId<?>, List<TermBucket>> returnMap = new HashMap<TransactionId<?>, List<TermBucket>>();
	for (TransactionId<?> transactionId : transactionIds)
	returnMap.put(transactionId, this.getBuckets(transactionId));
	return returnMap;
	}

	public List<IngestReceipt> query(QueryExpression queryExpression)
	throws QueryServiceException {
	Connection conn = null;
	Statement stmt = null;
	ResultSet rs = null;
	try {
	conn = this.dataSource.getConnection();
	stmt = conn.createStatement();
	String sqlQuery = "SELECT workflow_instance_id,start_date_time FROM workflow_instances WHERE workflow_instance_id IN (" + this.getSqlQuery(queryExpression) + ")";
	LOG.log(Level.INFO, "Performing Query: " + sqlQuery);
	rs = stmt.executeQuery(sqlQuery);

	List<IngestReceipt> receipts = new Vector<IngestReceipt>();
	while (rs.next())
	receipts.add(new IngestReceipt(new LongTransactionIdFactory().createTransactionId(rs.getString("workflow_instance_id")), DateConvert.isoParse(rs.getString("start_date_time"))));
	return receipts;
	}catch (Exception e) {
	throw new QueryServiceException("Failed to query Workflow Instances Database : " + e.getMessage(), e);
	}finally {
	try {
	conn.close();
	}catch(Exception e) {}
	try {
	stmt.close();
	}catch(Exception e) {}
	try {
	rs.close();
	}catch(Exception e) {}
	}
	}

	public List<IngestReceipt> query(QueryExpression queryExpression, int startIndex, int endIndex) throws QueryServiceException {
	Connection conn = null;
	Statement stmt = null;
	ResultSet rs = null;
	try {
	conn = this.dataSource.getConnection();
	stmt = conn.createStatement();
	String sqlQuery = "SELECT workflow_instance_id,start_date_time FROM workflow_instances WHERE workflow_instance_id IN (" + this.getSqlQuery(queryExpression) + ")";
	LOG.log(Level.INFO, "Performing Query: " + sqlQuery);
	rs = stmt.executeQuery(sqlQuery);

	List<IngestReceipt> receipts = new Vector<IngestReceipt>();
	int index = 0;
	while (startIndex > index && rs.next()) index++;
	while (rs.next() && index++ <= endIndex)
	receipts.add(new IngestReceipt(new LongTransactionIdFactory().createTransactionId(rs.getString("workflow_instance_id")), DateConvert.isoParse(rs.getString("start_date_time"))));
	return receipts;
	}catch (Exception e) {
	throw new QueryServiceException("Failed to query Workflow Instances Database : " + e.getMessage(), e);
	}finally {
	try {
	conn.close();
	}catch(Exception e) {}
	try {
	stmt.close();
	}catch(Exception e) {}
	try {
	rs.close();
	}catch(Exception e) {}
	}
	}

	public int sizeOf(QueryExpression queryExpression)
	throws QueryServiceException {
	Connection conn = null;
	Statement stmt = null;
	ResultSet rs = null;
	try {
	conn = this.dataSource.getConnection();
	stmt = conn.createStatement();
	String sqlQuery = "SELECT COUNT(workflow_instance_id) AS numInstances FROM workflow_instances WHERE workflow_instance_id IN (" + this.getSqlQuery(queryExpression) + ")";
	LOG.log(Level.INFO, "Performing Query: " + sqlQuery);
	rs = stmt.executeQuery(sqlQuery);

	int numInstances = 0;
	while (rs.next())
	numInstances = rs.getInt("numInstances");

	return numInstances;
	} catch (Exception e) {
	throw new QueryServiceException(
	"Failed to get size of query in Workflow Instances Database : "
	+ e.getMessage(), e);
	} finally {
	try {
	conn.close();
	} catch (Exception e) {
	}
	try {
	stmt.close();
	} catch (Exception e) {
	}
	try {
	rs.close();
	} catch (Exception e) {
	}
	}
	}

	private String getSqlQuery(QueryExpression queryExpression) throws QueryServiceException, UnsupportedEncodingException {
	String sqlQuery = null;
	if (queryExpression instanceof QueryLogicalGroup) {
	QueryLogicalGroup qlg = (QueryLogicalGroup) queryExpression;
	sqlQuery = "(" + this.getSqlQuery(qlg.getExpressions().get(0));
	String op = qlg.getOperator() == QueryLogicalGroup.Operator.AND ? "INTERSECT" : "UNION";
	for (int i = 1; i < qlg.getExpressions().size(); i++)
	sqlQuery += ") " + op + " (" + this.getSqlQuery(qlg.getExpressions().get(i));
	sqlQuery += ")";
	}else if (queryExpression instanceof ComparisonQueryExpression){
	ComparisonQueryExpression cqe = (ComparisonQueryExpression) queryExpression;
	String operator = null;
	if (cqe.getOperator().equals(ComparisonQueryExpression.Operator.EQUAL_TO)) {
	operator = "=";
	} else if (cqe.getOperator().equals(ComparisonQueryExpression.Operator.GREATER_THAN)) {
	operator = ">";
	} else if (cqe.getOperator().equals(ComparisonQueryExpression.Operator.GREATER_THAN_EQUAL_TO)) {
	operator = ">=";
	} else if (cqe.getOperator().equals(ComparisonQueryExpression.Operator.LESS_THAN)) {
	operator = "<";
	} else if (cqe.getOperator().equals(ComparisonQueryExpression.Operator.LESS_THAN_EQUAL_TO)) {
	operator = "<=";
	} else {
	throw new QueryServiceException("Invalid ComparisonQueryExpression Operator '" + cqe.getOperator() + "'");
	}

	sqlQuery = "SELECT DISTINCT workflow_instance_id FROM workflow_instance_metadata WHERE workflow_met_key = '" + cqe.getTerm().getName() + "' AND (";
	for (int i = 0; i < cqe.getTerm().getValues().size(); i++) {
	String value = cqe.getTerm().getValues().get(i);
	sqlQuery += "workflow_met_val " + operator + " '" + URLEncoder.encode(value, "UTF-8") + "'";
	if ((i + 1) < cqe.getTerm().getValues().size())
	sqlQuery += "OR";
	}
	sqlQuery += ")";
	}else if (queryExpression instanceof NotQueryExpression) {
	NotQueryExpression nqe = (NotQueryExpression) queryExpression;
	sqlQuery = "SELECT DISTINCT workflow_instance_id FROM workflow_instance_metadata WHERE NOT (" + this.getSqlQuery(nqe.getQueryExpression()) + ")";
	}else if (queryExpression instanceof StdQueryExpression) {
	sqlQuery = "SELECT DISTINCT workflow_instance_id FROM workflow_instance_metadata";
	}else {
	throw new QueryServiceException("Invalid QueryExpression '" + queryExpression.getClass().getCanonicalName() + "'");
	}
	return sqlQuery;
	}

	}