EF Core UseIdentityColumns

#csharp #dotnetcore #database #efcore

Introduction

UseIdentityColumns is useful to set a custom seed and increment value, such as starting IDs at 1000 instead of 1 or starting at 1 and configuring the increment, for example, starting at 1 and incrementing by 10.

💡 Only for SQL Server

Product	Versions
Entity Framework Core	6.0, 7.0, 8.0, 9.0, 10.0

Used

Microsoft Visual Studio 2026
NET 10 Framework
EF Core 10.0.8

Model for demonstrations

public partial class Customer
{
    public int CustomerId { get; set; }

    public string FirstName { get; set; }

    public string LastName { get; set; }
}

Start primary key at 100, increment by 1

A business rule requires the Customer CustomerId to start at 100 and increment by 1.

Pass 100 into UseIdentityColumns.

Start primary key at 10, increment by 10

A business rule requires the Customer CustomerId to start at 10 and increment by 10.

Sample code

Source code

Has been set up to create the database each time the console project runs to try out different configurations for UseIdentityColumns.

The connection string is in appsettings.json

{
  "ConnectionStrings": {
    "MainConnection": "Data Source=(localdb)\\MSSQLLocalDB;Initial Catalog=EF_IdentityOptions;Integrated Security=True;Encrypt=False"
  }
}