a simple question about "ResultSet"

[feng lee]

if there is no data that is eligible for the where condition.what dose the query return.is the ResultSet return null?
Thanks in advance!

[Sandeep Jain]

ResultSet object is never returned as null if no rows are returned from database.
A ResultSet maintains a cursor pointing to its current row of data. Initially the cursor is positioned before the first row. The next method moves the cursor to the next row.

[Blake Minghelli]

Just to expand a little...
If your first rs.next() call returns false then that means no rows were returned by your query.
For example:

 
int counter = 0;
ResultSet rs = statement.executeQuery("SELECT...");
while (rs.next()); // returns false when there are no more rows to process
   counter++;
   // do some processing on this record
}
if (counter == 0) {
  // No rows returned
}