Bug Report: ResultSet.isLast() returns false when queries return zero rows

Question

When calling the method isLast() on a resultset that contains zero (0) rows, false is returned. If a resultset contains no rows, isLast() should return true because returning false would indicate that there are more rows to be retrieved.
Try the following Java source:
import java.io.*;
import java.sql.*;
import java.util.*;
import oracle.jdbc.driver.*;
public class Test2 {
public static void main (String [] args) throws Exception {
Connection conn = null;
String jdbcURL = "jdbc:oracle:thin:@" +
"(DESCRIPTION=(ADDRESS=(HOST=<host computer>)"+
"(PROTOCOL=tcp)(PORT=<DB port number>))"+
"(CONNECT_DATA=(SID=<Oracle DB instance>)))";
String userId = "userid";
String password = "password";
try{
// Load the Oracle JDBC Driver and register it.
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
// *** The following statement creates a database connection object
// using the DriverManager.getConnection method. The first parameter is
// the database URL which is constructed based on the connection parameters
// specified in ConnectionParams.java.
// The URL syntax is as follows:
// "jdbc:oracle:<driver>:@<db connection string>"
// <driver>, can be 'thin' or 'oci8'
// <db connect string>, is a Net8 name-value, denoting the TNSNAMES entry
conn = DriverManager.getConnection(jdbcURL, userId, password);
} catch(SQLException ex){ //Trap SQL errors
// catch error
//conn = new OracleDriver().defaultConnection(); // Connect to Oracle 8i (8.1.7), use Oracle thin client.
PreparedStatement ps = conn.prepareStatement("select 'a' from dual where ? = ?", ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY); // Use any query that will return zero rows.
ps.setInt(1, 1); // Set the params so that the query returns 0 rows.
ps.setInt(2, 2);
ResultSet rs = ps.executeQuery();
System.out.println("1. Last here? " + rs.isLast());
while (rs.next()) {
// do whatever
System.out.println("2. Last here? " + rs.isLast());
ps.close();
rs.close();
EXPECTED RESULT -
1. Last here? true
2. Last here? true
ACTUAL RESULT -
1. Last here? false
2. Last here? false
This happens to me on Oracle 9.2.0.1.0.

Answer 1

387561,
For your information, I discovered this problem from
running a query that did access an actual DB table.
Try it and let me know.I did say I was only guessing, and yes, I did try it (after I posted my reply, and before I read yours). And I did check the query plan for the queries I tried -- to verify that they were actually doing some database "gets".
In any case, the usual way that I determine whether a "ResultSet" is empty is when the very first invocation of method "next()" returns 'false'. Is that not sufficient for you?
Good Luck,
Avi.