JDBC Tutorials - Herong's Tutorial Examples - v3.14, by Herong Yang
What Is ResultSet?
This section describes what is a ResultSet object.
A ResultSet object represents the output table of data resulted from a SELECT query statement with following features:
When you execute a SELECT statement with the executeQuery() method, it will return a ResultSet object to you. Here is a Java example program that catches the ResultSet object:
/* DerbySelectCount.java * Copyright (c) HerongYang.com. All Rights Reserved. */ import java.sql.*; public class DerbySelectCount { public static void main(String [] args) { Connection con = null; try { con = DriverManager.getConnection("jdbc:derby://localhost/TestDB"); Statement sta = con.createStatement(); // Catch the ResultSet object ResultSet res = sta.executeQuery( "SELECT COUNT(*) FROM Profile"); // Move the cursor to the first row res.next(); // Get the value from the first column of the current row System.out.println("Number of profiles: "+res.getInt(1)); // Close the ResultSet object res.close(); sta.close(); con.close(); } catch (Exception e) { System.err.println("Exception: "+e.getMessage()); } } }
Here is the result of this program:
Number of profiles: 9
Question: How many rows and columns are there in this ResultSet object?
Table of Contents
JDBC (Java Database Connectivity) Introduction
Installing and Running Derby (Java DB)
Derby (Java DB) JDBC DataSource Objects
Derby (Java DB) - DML Statements
►Derby (Java DB) - ResultSet Objects of Queries
ResultSet Cursor and Scrollability
ResultSet Cursor Initial Position: Before First Row
Retrieving Column Values with getXXX() Methods
ResultSet Default Type: Forward-only
Scrollable ResultSet and Moving Cursor Backward
ResultSet Objects with Update Capability
insertRow() - Inserting New Rows through ResultSet Objects
updateXXX() - Updating Column Values for Row Update or Insert
deleteRow() - Deleting Rows through ResultSet Objects
Derby (Java DB) - PreparedStatement
Summary of JDBC Drivers and Database Servers