Get Number of Rows returned by ResultSet in Java

Question

I have used a ResultSet that returns certain number of rows. My code is something like this:

ResultSet res = getData(); if(!res.next()) {     System.out.println("No Data Found"); } while(res.next()) {     // code to display the data in the table. } 

Is there any method to check the number of rows returned by the ResultSet? Or do I have to write my own?

Answer 1

First, you should create Statement which can be move cursor by command:

Statement stmt = con.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY); 

Then retrieve the ResultSet as below:

ResultSet rs = stmt.executeQuery(...); 

Move cursor to the latest row and get it:

if (rs.last()) {     int rows = rs.getRow();     // Move to beginning     rs.beforeFirst();     ... } 

Then rows variable will contains number of rows returned by sql

Answer 2

You could use a do ... while loop instead of a while loop, so that rs.next() is called after the loop is executed, like this:

if (!rs.next()) {                            //if rs.next() returns false                                              //then there are no rows.     System.out.println("No records found");  } else {     do {         // Get data from the current row and use it     } while (rs.next()); } 

Or count the rows yourself as you're getting them:

int count = 0;  while (rs.next()) {     ++count;     // Get data from the current row and use it }  if (count == 0) {     System.out.println("No records found"); }