JDBC Tutorials - Herong's Tutorial Examples - Version 3.02, by Dr. Herong Yang

JDBC Tutorials - Herong's Tutorial Examples

∟Java DB (Derby) - ResultSet Objects of Queries

∟ResultSet Objects with Update Capability

ResultSet objects can also be created with update capability so that they can be used to perform the same functionalities as the "UPDATE", "INSERT" and "DELETE" SQL statements. To create a ResultSet object with update capability, you must follow several guidelines:

• The ResultSet object must be created with a SELECT statement by the executeQury() method on a Statement object.
• The Statement object must be created with ResultSet.CONCUR_UPDATABLE as the concurrency type.
• The SELECT statement must have a single underlying table, with no joins and no aggregations (GROUP BY).
• The underlying table must have a primary key column, which must be selected in result by the SELECT statement.
• All columns that require user values (nonnullable and no default values) in the underlying table must be selected in result by the SELECT statement.
• The JDBC driver must support updatability.

Of course, the Derby JDBC driver does support updatability. So I wrote the following sample program to update one row of the Profile table:

Here is a sample program that updated one row in the Profile table through a ResultSet object:

/* DerbyUpdateResultSet.java
 - Copyright (c) 2015, HerongYang.com, All Rights Reserved.
 */
import java.sql.*;
public class DerbyUpdateResultSet {
  public static void main(String [] args) {
    Connection con = null;
    try {
      con = DriverManager.getConnection(
        "jdbc:derby://localhost/TestDB");

// Create a Statement for scrollable ResultSet
      Statement sta = con.createStatement(
        ResultSet.TYPE_FORWARD_ONLY,
        ResultSet.CONCUR_UPDATABLE);

// Catch the ResultSet object
      ResultSet res = sta.executeQuery(
        "SELECT * FROM Profile WHERE ID = 9");

// Check ResultSet's updatability
      if (res.getConcurrency() == ResultSet.CONCUR_READ_ONLY) {
        System.out.println("ResultSet non-updatable.");
      } else {
        System.out.println("ResultSet updatable.");
      }

// Move the cursor to the first row
      res.next();

// Get the current first name and last name
      String firstName = res.getString("FirstName");
      String lastName = res.getString("LastName");
      System.out.println("Current name: "+firstName+" "+lastName);

// Set the new first name and last name
      res.updateString("FirstName", "Johnny");
      res.updateString("LastName", "Caprio");
      res.updateRow();

// Can not get the updated first name and last name back
//      firstName = res.getString("FirstName");
//      lastName = res.getString("LastName");
//      System.out.println("Updated name: "+firstName+" "+lastName);
      System.out.println("Updated name: Johnny Caprio");

// Close ResultSet and Statement
      res.close();
      sta.close();

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

Here is the output:

ResultSet updatable.
Current name: 1352 17d9
Updated name: Johnny Caprio

Notice that I commented out 3 lines of code, because getXXX() methods give me exceptions when called after the updateRow() method. This is not mentioned in the JDBC API document.

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

ResultSet Objects with Update Capability - Updated in 2017, by Dr. Herong Yang