"INSERT INTO" Statements with INDENTITY Columns

JDBC Tutorials - Herong's Tutorial Examples - Version 3.03, by Dr. Herong Yang

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 INDENTITY columns.

An INDENTITY column is a special column in a table that defined to have it value automatically added with a sequence number generator. An INDENTITY column is normally used for the primary key column in a table.

For example, we can add a new column, CustomID, into my Customer table and make it as an INDENTITY column.

C:\herong>"\Progra^1\Microsoft SQL Server\Client SDK
   \ODBC\110\Tools\Binn\SQLCMD.exe" 
   -S localhost\SQLEXPRESS -U sa -P HerongY@ng

1> use AdventureWorks2014
2> go
1> alter table Herong.Customer add CustomerID int IDENTITY
2> go

If you try to add values to an INDENTITY column in INSERT statements, you will get an error as shown in the sample program below:

/* InsertIdentity.java
 - Copyright (c) 2015, HerongYang.com, All Rights Reserved.
 */
import java.sql.*;
public class InsertIdentity {
  public static void main(String [] args) {
    Connection con = null;
    try {

      con = DriverManager.getConnection(
          "jdbc:sqlserver://localhost\\SQLEXPRESS;"
        + "user=sa;password=HerongY@ng;"
        + "database=AdventureWorks2014");
      Statement sta = con.createStatement(); 

// insert a single row
      int count = sta.executeUpdate(
        "INSERT INTO Herong.Customer"
        + " (CustomerID, FirstName, LastName, ModifiedDate)"
        + " VALUES (1001, 'Herong', 'Yang', '2007-04-01')");
      System.out.println("Number of rows inserted: "+count);

      sta.close();
      con.close();        
    } catch (Exception e) {
      e.printStackTrace();
    }
  }
}

Here is the error message from this program:

C:\herong>\Progra~1\java\jdk1.8.0_45\bin\java 
   -cp .;\local\lib\sqljdbc42.jar InsertIdentity

com.microsoft.sqlserver.jdbc.SQLServerException: 
Cannot insert explicit value for identity column 
in table 'Customer' when IDENTITY_INSERT is set to OFF.

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

Java DB (Derby) - PreparedStatement

MySQL Installation on Windows