ResultSet Cursor Initial Position: Before First Row

This section describes the ResultSet cursor initial position: before first row. next() should be called to move the cursor to the first row.

Right after the ResultSet object is returned from the executeQuery() call, the ResultSet cursor is positioned before the first row. You need to call next() once to move the cursor to the first row. If you missed this call, you will get an error message as shown by this sample program:

/* DerbyResultSetNoNext.java
 - Copyright (c) 2015, HerongYang.com, All Rights Reserved.
 */
import java.sql.*;
public class DerbyResultSetNoNext {
  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 * FROM Profile");

// Skip calling next()
//    res.next();

// Try to get column values
      String firstName = res.getString("FirstName");
      String lastName = res.getString("LastName");

// Close ResultSet
      res.close();

      sta.close();
      con.close();        
    } catch (Exception e) {
      System.err.println("Exception: "+e.getMessage());
    }
  }
}

Run this program to see the error if res.next() is not called after executeQuery():

Exception: Invalid operation at current cursor position.

Last update: 2015.

Table of Contents

 About This Book

 JDBC (Java Database Connectivity) Introduction

 JDK (Java SE) Installation

 Installing and Running Java DB - Derby

 Derby (Java DB) JDBC Driver

 Derby (Java DB) JDBC DataSource Objects

 Java DB (Derby) - DML Statements

Java DB (Derby) - ResultSet Objects of Queries

 What Is ResultSet?

 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

 MySQL Installation on Windows

 MySQL JDBC Driver (MySQL Connector/J)

 MySQL - PreparedStatement

 MySQL - Reference Implementation of JdbcRowSet

 MySQL - JBDC CallableStatement

 MySQL CLOB (Character Large Object) - TEXT

 MySQL BLOB (Binary Large Object) - BLOB

 Oracle Express Edition Installation on Windows

 Oracle JDBC Drivers

 Oracle - Reference Implementation of JdbcRowSet

 Oracle - PreparedStatement

 Oracle - JBDC CallableStatement

 Oracle CLOB (Character Large Object) - TEXT

 Oracle BLOB (Binary Large Object) - BLOB

 Microsoft SQL Server 2005 Express Edition

 Microsoft JDBC Driver for SQL Server - sqljdbc42.jar

 Microsoft JDBC Driver - Query Statements and Result Sets

 Microsoft JDBC Driver - DatabaseMetaData Object

 Microsoft JDBC Driver - DDL Statements

 Microsoft JDBC Driver - DML Statements

 SQL Server - PreparedStatement

 SQL Server CLOB (Character Large Object) - TEXT

 SQL Server BLOB (Binary Large Object) - BLOB

 JDBC-ODBC Bridge Driver - sun.jdbc.odbc.JdbcOdbcDriver

 JDBC-ODBC Bridge Driver - Flat Text Files

 JDBC-ODBC Bridge Driver - MS Access

 JDBC-ODBC Bridge Driver - MS SQL Server

 Summary of JDBC Drivers and Database Servers

 Additional Tutorial Notes to Be Added

 Outdated Tutorials

 References

 PDF Printing Version