Executing a relational query

Example – Executing a simple query returning tabular data

//create a QueryConnector for executing queries:

		QueryConnector queryConnector = new QueryConnector();

		

		//build a query:

		BusinessQuery query1 = buildBusinessQuery();

		

		//create a list of queries to execute:

		List queries = Collections.singletonList(query1);

		

		//execute the queries:

		Map results = queryConnector.retrieveQueryResultMap(queries);

		

		//fetch the result for the query1 from the map:
		 

		ResultSetInterface genericResultSet = (ResultSetInterface) results.get(query1.getID());

		

		//extract the Java SQL ResultSet contained in the generic wrapper:

		//(casting it since we know that query1 will return a java.sql.ResultSet 
		instance)

		java.sql.ResultSet sqlResultSet = (java.sql.ResultSet) genericResultSet.getResultSet();

		

		//loop through the rows, printing the values of the first column:

		while (sqlResultSet.next()) {

		String firstColumnValue = sqlResultSet.getString(1);

		System.out.println(firstColumnValue);

		}

		

		//close the result set just retrieved and the server connection:

		int closeConnectionAndResultSet =

		QueryConnector.CloseOptions.ALL_RESULTSET_OPTIONS

		| QueryConnector.CloseOptions.ALL_CONNECTION_OPTIONS;

		

		queryConnector.closeResources(getSessionContext(), closeConnectionAndResultSet);

The result of running this program will be for the values of the first column to be printed on the console, e.g.

Joyce   
Jane    
Louise  
Alice   
Barbara 
Carol   
Judy    
Janet   
Mary    
Thomas  
James   
John    
Robert  
Jeffrey 
Alfred  
Henry   
Ronald  
William 
Philip

For the SAS classroom dataset if "name" is the first data item in the query built.