Row Not Found from executeQuery

Question

Statement sql = con.createStatement();
ResultSet rs = sql.executeQuery("select * from emp);
How do you know if the executeQuery has returned any rows ? How do you test for row not found.
thanks

Answer 1

I'm a bit unclear on what this topic is about . Are you trying to prove a point that you could write a driver that works the way you say and still be within JDBC specs, or are you actually having a problem? I've used JDBC Drivers from many vendors and the code I gave you would work with all of them as described. The following was cut and pasted from the online docuementation and would appear to is is from the Java Doc for the ResultSet Interface and it seems to validate that the code I gave you is correct (assuming that a null ResultSet cannot be returned when using executeQuery).
"A ResultSet object 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, and because it returns false when there are no more rows in the ResultSet object, it can be used in a while loop to iterate through the result set. "
Here is the online documentation that states that a ResultSet will NEVER be null when invoking executeQuery:
executeQuery
public ResultSet executeQuery(String sql)
throws SQLExceptionExecutes the given SQL statement, which returns a single ResultSet object.
Parameters:
sql - an SQL statement to be sent to the database, typically a static SQL SELECT statement
Returns:
a ResultSet object that contains the data produced by the given query; never null
Throws:
SQLException - if a database access error occurs or the given SQL statement produces anything other than a single ResultSet object
So, I would reiterate that this is not a code problem. If you are getting an Exception, then the problem lies elsewhere.