keep-identity-values-when-bulk-importing-data-sql-server.md

title	Keep Identity Values When Bulk Importing Data
description	When you bulk import data that contains identity values to a SQL Server instance, by default, it assigns new values. You can choose to keep the original values.
author	rwestMSFT
ms.author	randolphwest
ms.date	05/19/2025
ms.service	sql
ms.subservice	data-movement
ms.topic	concept-article
helpviewer_keywords	identity values [SQL Server], bulk imports data formats [SQL Server], identity values bulk importing [SQL Server], identity values
monikerRange	>=aps-pdw-2016 || =azuresqldb-current || =azure-sqldw-latest || >=sql-server-2016 || >=sql-server-linux-2017 || =azuresqldb-mi-current

Keep identity values when bulk importing data (SQL Server)

[!INCLUDESQL Server Azure SQL Database Synapse Analytics PDW]

Data files that contain identity values can be bulk imported into an instance of Microsoft SQL Server.

By default, the values for the identity column in the data file that is imported are ignored and [!INCLUDEssNoVersion] assigns unique values automatically. The unique values are based on the seed and increment values that are specified during table creation.

If the data file does not contain values for the identifier column in the table, use a format file to specify that the identifier column in the table should be skipped when importing data. See Use a Format File to Skip a Table Column (SQL Server) for additional information.

Keep identity values

To prevent [!INCLUDEssNoVersion] from assigning identity values while bulk importing data rows into a table, use the appropriate keep-identity command qualifier. When you specify a keep-identity qualifier, [!INCLUDEssNoVersion] uses the identity values in the data file.

These qualifiers are as follows:

Command	Keep-identity qualifier	Qualifier type
bcp	-E	Switch
BULK INSERT	KEEPIDENTITY	Argument
INSERT ... SELECT * FROM OPENROWSET(BULK...)	KEEPIDENTITY	Table hint

For more information, see bcp Utility, BULK INSERT (Transact-SQL), OPENROWSET BULK (Transact-SQL), INSERT (Transact-SQL), SELECT (Transact-SQL), and Table hints (Transact-SQL).

Note

To create an automatically incrementing number that can be used in multiple tables or that can be called from applications without referencing any table, see Sequence Numbers.

Example Test Conditions

The examples in this topic are based on the table, data file, and format file defined below.

Sample Table

The script below creates a test database and a table named myIdentity. Execute the following Transact-SQL in Microsoft [!INCLUDEssManStudioFull] (SSMS):

CREATE DATABASE TestDatabase;
GO

USE TestDatabase;
CREATE TABLE dbo.myIdentity ( 
   PersonID smallint IDENTITY(1,1) NOT NULL,
   FirstName varchar(25) NOT NULL,
   LastName varchar(30) NOT NULL,
   BirthDate date
   );

Sample Data File

Using Notepad, create an empty file D:\BCP\myIdentity.bcp and insert the data below.

3,Anthony,Grosse,1980-02-23
2,Alica,Fatnowna,1963-11-14
1,Stella,Rosenhain,1992-03-02
4,Miller,Dylan,1954-01-05

Alternatively, you can execute the following PowerShell script to create and populate the data file:

cls
# revise directory as desired
$dir = 'D:\BCP\';

$bcpFile = $dir + 'myIdentity.bcp';

# Confirm directory exists
IF ((Test-Path -Path $dir) -eq 0)
{
    Write-Host "The path $dir does not exist; please create or modify the directory.";
    RETURN;
};

# clear content, will error if file does not exist, can be ignored
Clear-Content -Path $bcpFile -ErrorAction SilentlyContinue;

# Add data
Add-Content -Path $bcpFile -Value '3,Anthony,Grosse,1980-02-23';
Add-Content -Path $bcpFile -Value '2,Alica,Fatnowna,1963-11-14';
Add-Content -Path $bcpFile -Value '1,Stella,Rosenhain,1992-03-02';
Add-Content -Path $bcpFile -Value '4,Miller,Dylan,1954-01-05';

#Review content
Get-Content -Path $bcpFile;
Invoke-Item $bcpFile;

Sample Non-XML format file

SQL Server support two types of format file: non-XML format and XML format. The non-XML format is the original format that is supported by earlier versions of SQL Server. For more information, see Use Non-XML format files (SQL Server).

The following command will use the bcp utility to generate a non-xml format file, myIdentity.fmt, based on the schema of myIdentity.

• To use a bcp command to create a format file, specify the format argument and use nul instead of a data-file path.
• The format option also requires the -f option.
• c is used to specify character data
• t, is used to specify a comma as a field terminator
• T is used to specify a trusted connection using integrated security.

At a command prompt, enter the following command:

bcp TestDatabase.dbo.myIdentity format nul -c -f D:\BCP\myIdentity.fmt -t, -T

REM Review file
Notepad D:\BCP\myIdentity.fmt

Important

Ensure your non-XML format file ends with a carriage return\line feed. Otherwise you will likely receive the following error message:

SQLState = S1000, NativeError = 0
Error = [Microsoft][ODBC Driver 13 for SQL Server]I/O error while reading BCP format file

Examples

The examples use the database, datafile, and format files created in this article.

Use bcp and keep Identity Values without a format file

The -E switch.

At a command prompt, enter the following command:

REM Truncate table (for testing)
SQLCMD -Q "TRUNCATE TABLE TestDatabase.dbo.myIdentity;"

REM Import data
bcp TestDatabase.dbo.myIdentity IN D:\BCP\myIdentity.bcp -T -c -t, -E

REM Review results
SQLCMD -Q "SELECT * FROM TestDatabase.dbo.myIdentity;"

Use bcp and keep Identity values with a non-XML format file

The -E and -f switches.

At a command prompt, enter the following command:

REM Truncate table (for testing)
SQLCMD -Q "TRUNCATE TABLE TestDatabase.dbo.myIdentity;"

REM Import data
bcp TestDatabase.dbo.myIdentity IN D:\BCP\myIdentity.bcp -f D:\BCP\myIdentity.fmt -T -E

REM Review results
SQLCMD -Q "SELECT * FROM TestDatabase.dbo.myIdentity;"

Use bcp and generated Identity values without a format file

Using defaults.

At a command prompt, enter the following command:

REM Truncate table (for testing)
SQLCMD -Q "TRUNCATE TABLE TestDatabase.dbo.myIdentity;"

REM Import data
bcp TestDatabase.dbo.myIdentity IN D:\BCP\myIdentity.bcp -T -c -t,

REM Review results
SQLCMD -Q "SELECT * FROM TestDatabase.dbo.myIdentity;"

Use bcp and generated Identity Values with a non-XML format file

Use defaults and -f switch.

At a command prompt, enter the following command:

REM Truncate table (for testing)
SQLCMD -Q "TRUNCATE TABLE TestDatabase.dbo.myIdentity;"

REM Import data
bcp TestDatabase.dbo.myIdentity IN D:\BCP\myIdentity.bcp -f D:\BCP\myIdentity.fmt -T

REM Review results
SQLCMD -Q "SELECT * FROM TestDatabase.dbo.myIdentity;"

Use BULK INSERT and keep Identity values without a format file

The KEEPIDENTITY argument.

Execute the following Transact-SQL in Microsoft [!INCLUDEssManStudioFull] (SSMS):

USE TestDatabase;
GO

TRUNCATE TABLE dbo.myIdentity; -- for testing
BULK INSERT dbo.myIdentity
    FROM 'D:\BCP\myIdentity.bcp'
    WITH (
        DATAFILETYPE = 'char',  
        FIELDTERMINATOR = ',',  
        KEEPIDENTITY
        );

-- review results
SELECT * FROM TestDatabase.dbo.myIdentity;

Use BULK INSERT and keep Identity values with a non-XML format file

The KEEPIDENTITY and the FORMATFILE arguments.

Execute the following Transact-SQL in Microsoft [!INCLUDEssManStudioFull] (SSMS):

USE TestDatabase;
GO

TRUNCATE TABLE dbo.myIdentity; -- for testing
BULK INSERT dbo.myIdentity
   FROM 'D:\BCP\myIdentity.bcp'
   WITH (
        FORMATFILE = 'D:\BCP\myIdentity.fmt',
        KEEPIDENTITY
        );

-- review results
SELECT * FROM TestDatabase.dbo.myIdentity;

Use BULK INSERT and generated Identity values without a format file

Using defaults.

Execute the following Transact-SQL in Microsoft [!INCLUDEssManStudioFull] (SSMS):

USE TestDatabase;
GO

TRUNCATE TABLE dbo.myIdentity;  -- for testing
BULK INSERT dbo.myIdentity
   FROM 'D:\BCP\myIdentity.bcp'
   WITH (
      DATAFILETYPE = 'char',  
      FIELDTERMINATOR = ','
      );

-- review results
SELECT * FROM TestDatabase.dbo.myIdentity;

Use BULK INSERT and generated Identity values with a non-XML format file

Using defaults and FORMATFILE argument.

Execute the following Transact-SQL in Microsoft [!INCLUDEssManStudioFull] (SSMS):

USE TestDatabase;
GO

TRUNCATE TABLE dbo.myIdentity;  -- for testing
BULK INSERT dbo.myIdentity
   FROM 'D:\BCP\myIdentity.bcp'
   WITH (
        FORMATFILE = 'D:\BCP\myIdentity.fmt'
        );

-- review results
SELECT * FROM TestDatabase.dbo.myIdentity;

Use OPENROWSET BULK and keep Identity values with a non-XML format file

The KEEPIDENTITY table hint and FORMATFILE argument.

Execute the following Transact-SQL in Microsoft [!INCLUDEssManStudioFull] (SSMS):

USE TestDatabase;
GO

TRUNCATE TABLE dbo.myIdentity;  -- for testing
INSERT INTO dbo.myIdentity
WITH (KEEPIDENTITY) 
(PersonID, FirstName, LastName, BirthDate)
    SELECT *
    FROM OPENROWSET (
        BULK 'D:\BCP\myIdentity.bcp', 
        FORMATFILE = 'D:\BCP\myIdentity.fmt'  
        ) AS t1;

-- review results
SELECT * FROM TestDatabase.dbo.myIdentity;

Use OPENROWSET BULK and generated Identity values with a non-XML format file

Using defaults and the FORMATFILE argument.

Execute the following Transact-SQL in Microsoft [!INCLUDEssManStudioFull] (SSMS):

USE TestDatabase;
GO

TRUNCATE TABLE dbo.myIdentity;  -- for testing
INSERT INTO dbo.myIdentity
(FirstName, LastName, BirthDate)
    SELECT FirstName, LastName, BirthDate
    FROM OPENROWSET (
        BULK 'D:\BCP\myIdentity.bcp', 
        FORMATFILE = 'D:\BCP\myIdentity.fmt'  
        ) AS t1;

-- review results
SELECT * FROM TestDatabase.dbo.myIdentity;

Related Tasks

• Keep nulls or default values during bulk import (SQL Server)

• Prepare data for bulk export or import

To use a format file

• Create a format file with bcp (SQL Server)

• Use a format file to bulk import data (SQL Server)

• Use a format file to map table columns to data-file fields (SQL Server)

• Use a format file to skip a data field (SQL Server)

• Use a Format File to Skip a Table Column (SQL Server)

To use data formats for bulk import or bulk export

• Import native and character format data from earlier versions of SQL Server

• Use character format to import or export data (SQL Server)

• Use native format to import or export data (SQL Server)

• Use unicode character format to import or export data (SQL Server)

• Use Unicode Native Format to Import or Export Data (SQL Server)

To specify data formats for compatibility when using bcp

1. Specify field and row terminators (SQL Server)

2. Specify prefix length in data files using bcp (SQL Server)

3. Specify file storage type using bcp (SQL Server)

Related content

• BACKUP (Transact-SQL)
• bcp Utility
• BULK INSERT (Transact-SQL)
• OPENROWSET (Transact-SQL)
• Table hints (Transact-SQL)
• Format files to import or export data (SQL Server)