Question

m trying to loop through 3 resultsets and compare their values. bt its throwing this exception…could someone help me on where am going through?
here is the piece of code:

java.lang.Object[] reconciledPaymentDetails = null;

java.util.Vector shiftsVector = new java.util.Vector(1, 1);

String status = "";

try {

    Class.forName("org.postgresql.Driver");
    } 
catch (ClassNotFoundException ex) {
    Logger.getLogger(DBConnection.class.getName()).log(Level.SEVERE, null, ex);
   }
try {
    connDB = DriverManager.getConnection("jdbc:postgresql://" + hostName + ":" + portNumber + "/" + dbName, userName, password);

    System.out.println("Connection established : [" + connDB.toString() + "]");

    java.sql.Statement pstmt = connDB.createStatement();

    java.sql.Statement pstmtShifts = connDB.createStatement();

    java.sql.ResultSet rset = pstmt.executeQuery("SELECT DISTINCT payment_mode,transaction_type, credit FROM ac_cash_collection WHERE shift_no = '" + shiftNumber + "'");

    while (rset.next()) {

        java.sql.ResultSet rsetShifts = pstmtShifts.executeQuery("SELECT DISTINCT amount, shift_amount FROM ac_shift_collections WHERE shift_no = '" + shiftNumber + "' AND pay_mode ilike '"+rset.getString(1) +"'");

        while (rsetShifts.next()) {

            java.sql.ResultSet rset2 = pstmt.executeQuery("select debit from ac_cash_book where shift_no='"+shiftNumber+"'");


           while (rset2.next()){

                double debit =rset2.getDouble("debit");

                if((rset2.getDouble("debit")<=0 ))

             status = "no_banked";

               else if((rset2.getDouble("debit")==rsetShifts.getDouble("amount"))
                        && (rsetShifts.getDouble("amount"))< rsetShifts.getDouble("shift_amount"))
                        status= "BntClosed";
                else if (rset2.getDouble(1)==rsetShifts.getDouble("shift_amount"))
                    status ="bClosed";




            shiftsVector.addElement(rset.getString(1)+":"+rsetShifts.getString(1)+":"+status);

            } 
        }
    }

Answer 1

The documentation provides a clear explanation of this:

By default, only one ResultSet object per Statement object can be open
at the same time. Therefore, if the reading of one ResultSet object is
interleaved with the reading of another, each must have been generated
by different Statement objects. All execution methods in the Statement
interface implicitly close a statment’s current ResultSet object if an
open one exists.

So your options would be:

1. Use a different Statement instance for each query.
2. Collect all the results from each ResultSet (i.e. into a Set or a List) before moving on to the next one, and then run the comparison on the collected results instead of directly on the result-sets.