Tables with Primary Key Column "GENERATED ... AS IDENTITY"

This section describes how to create a table primary key column defined as 'GENERATED ... AS IDENTITY'.

Similar to Microsoft SQL Server, Derby supports IDENTITY columns to help you creating auto-incremented sequence values for primary key columns. Derby offers two variations of IDENTITY columns:

In order to try IDENTITY columns and provide a test table for testing DML (Data Manipulation Statements), I wrote the following program to create a table called "Profile" with the primary key column defined as an IDENTITY column:

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

// Creating a database table
      Statement sta = con.createStatement();
      int count = sta.executeUpdate(
        "CREATE TABLE Profile ("
        + " FirstName VARCHAR(20) NOT NULL,"
        + " LastName VARCHAR(20),"
        + " Point REAL DEFAULT 0.0,"
        + " BirthDate DATE DEFAULT '1999-12-31',"
        + " ModTime TIMESTAMP DEFAULT '2016-12-31 23:59:59.999')");
      System.out.println("Table created.");

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

When you run this example program for the first time, table Profile will be created. If you run it again, you will get an exception:

herong> java -cp %DERBY_HOME%\lib\derbyclient.jar
herong> java -cp $DERBY_HOME/lib/derbyclient.jar

Table created.

herong> java -cp %DERBY_HOME%\lib\derbyclient.jar
herong> java -cp $DERBY_HOME/lib/derbyclient.jar

Exception: Table/View 'PROFILE' already exists in Schema 'APP'.

Table of Contents

 About This Book

 JDBC (Java Database Connectivity) Introduction

 JDK (Java SE) Installation

 Installing and Running Derby (Java DB)

 Derby (Java DB) JDBC Driver

 Derby (Java DB) JDBC DataSource Objects

Derby (Java DB) - DML Statements

Tables with Primary Key Column "GENERATED ... AS IDENTITY"

 "INSERT INTO" Statements

 "INSERT INTO" Statements with INDENTITY Columns

 Handling Date and Timestamp Values

 "UPDATE" Statements

 "DELETE FROM" Statements

 Derby (Java DB) - ResultSet Objects of Queries

 Derby (Java DB) - PreparedStatement

 Summary of JDBC Drivers and Database Servers

 Using Connection Pool with JDBC

 Archived Tutorials


 Full Version in PDF/EPUB