JDBC Tutorials - Herong's Tutorial Examples - v3.13, 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 Java DB - Derby
Derby (Java DB) JDBC DataSource Objects
Java DB (Derby) - DML Statements
►Java DB (Derby) - 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
Java DB (Derby) - PreparedStatement
Summary of JDBC Drivers and Database Servers