Using Resultset in Java Program

Question

Resultset rs=stmt.executeQuery("select count(*) from feedsca group by score order by score");

Using the above java code above, am retrieving the counts of rows from the table named feedsCA.

While trying to retrieving the counts using rs.getInt(1),rs.getInt(2),rs.getInt(3), I end with an error saying as below,

Exception in thread "main" com.microsoft.sqlserver.jdbc.SQLServerException: The result set has no current row.
    at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(Unknown Source)
    at com.microsoft.sqlserver.jdbc.SQLServerResultSet.verifyResultSetHasCurrentRow(Unknown Source)
    at com.microsoft.sqlserver.jdbc.SQLServerResultSet.getterGetColumn(Unknown Source)
    at com.microsoft.sqlserver.jdbc.SQLServerResultSet.getInt(Unknown Source)
    at SimpleMail.main(SimpleMail.java:151)

UPDATE:

The above exception has been resolved.

But I get the following exception, for which I dont know the reason. Please advise.

Exception in thread "main" com.microsoft.sqlserver.jdbc.SQLServerException: The index 2 is out of range.
    at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(Unknown Source)
    at com.microsoft.sqlserver.jdbc.SQLServerResultSet.verifyValidColumnIndex(Unknown Source)
    at com.microsoft.sqlserver.jdbc.SQLServerResultSet.getterGetColumn(Unknown Source)
    at com.microsoft.sqlserver.jdbc.SQLServerResultSet.getInt(Unknown Source)
    at SimpleMail.main(SimpleMail.java:152)

This is how I have updated my program. Find me a logical way as I can understand well that the loop below will not work as required.

rs=stmt.executeQuery("select count(*) from feedsca group by score order by score");
while(rs.next()){
pw.printf(rowFormat, rs.getLong(1),"0",rs.getLong(2),rs.getLong(3));}

Answer 1

You have to move the cursor of the result set to a row - either by resultSet.first() or by resultSet.next(). Initially the cursor is pointing before the first row, hence your exception.

When you want to iterate the ResultSet:

while(rs.next()) {
    ...
}

Update: For your second problem - (as noted by Casablanca) your query seems to return only one column, and you are asking for a 2nd and 3rd - and they are not found. Note that in rs.getX(idx) idx is the column, not the row.