Queries that return no results cause exception

Question

When I run a query that returns no records, my program crashes and burns, giving me the error message that no data was found; something doesn't seem right about that. Shouldn't it be able to handle this situation? Does anyone know what I'm doing wrong? Thanks.

Answer 1

I'd rewrite your snippet this way:
// Here's where you get your data
String sql = "SELECT FiscalYear FROM Requests WHERE Agency = ?";                          
stmt = con.prepareStatement(sql);                     
stmt.setString(1, agency);
ResultSet result = stmt.executeQuery();                                                   
List fiscalYears = new ArrayList();
while (result.next())
    fiscalYears.add(result.getString("FiscalYear"));
result.close();
stmt.close();
// Here's where you do something with it.
int numFiscalYears = fiscalYears.size();
if (numFiscalYears > 0)
    for (int i = 0; i < numFiscalYears; ++i)
        if (i == 0)
            //if data was returned, get first row   
            //put FY value into echoPacket and send to client  
            echoPacket = DGramIt.toDatagram((String)fiscalYears.get(i), packet.getAddress(), packet.getPort());
            socket.send(echoPacket);                                                                  
        else
            //for each row of data    
            socket.receive(dummyPacket);//receive dummy packet         
            //put FY value into echoPacket and send to client      
            echoPacket = DGramIt.toDatagram((String)fiscalYears.get(i), packet.getAddress(), packet.getPort());    
            socket.send(echoPacket);   
else
    //if no data, send client message  
    //put message into echoPacket and send to client   
    echoPacket = DGramIt.toDatagram("no data", packet.getAddress(), packet.getPort());   
    socket.send(echoPacket);
}Separate out getting the results from what you do with them. - MOD