"INSERT INTO" Statements with INDENTITY Columns

JDBC Tutorials - Herong's Tutorial Examples

∟"INSERT INTO" Statements with INDENTITY Columns

This section describes what will happen if you try to insert rows with values for GENERATED ALWAYS AS IDENTITY columns.

An INDENTITY column is a special column in a table that is defined to have its values automatically added with a sequence number generator. An INDENTITY column is normally used for the primary key column in a table. For example, the ID column in the Profile table created in a previous tutorial is an INDENTITY column.

If an IDENTITY column is defined with "GENERATED ALWAYS AS IDENTITY" and you try to add values to this column in INSERT statements, you will get an error as shown in the sample program below:

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

// insert a single row
      int count = sta.executeUpdate(
        "INSERT INTO Profile"
        + " (ID, FirstName, LastName, ModTime)"
        + " VALUES (1001, 'Herong', 'Yang', '2017-04-01')");
      System.out.println("Number of rows inserted: "+count);

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

Here is the error message from this program:

Exception: Attempt to modify an identity column 'ID'.

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

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

Java DB (Derby) - ResultSet Objects of Queries

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 Express Edition

Microsoft JDBC Driver for SQL Server

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

Using Connection Pool with JDBC

Archived Tutorials

References

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