Switch to long Id

This document explains how to switch an entity id from int to long. It can be use similar to switch to GUID.
For this example, we have switch the id of the entity: Plane.

Transform the entity

Use long in the inheritance IEntity and in the Id type

    public class Plane : VersionedTable, IEntity<long>
    {
        /// <summary>
        /// Gets or sets the id.
        /// </summary>
        public long Id { get; set; }
        ....
    }

Transform the dto

Use long in the inheritance BaseDto

    public class PlaneDto : BaseDto<long>

Transform the mapper

Use long in the inheritance BaseMapper

    public class PlaneMapper : BaseMapper<PlaneDto, Plane, long>

Transform the related entities

If the entity id is reference by other table change the type in related entities.

  public class PlaneAirport : VersionedTable
  {
      /// <summary>
      /// Gets or sets the Plane.
      /// </summary>
      public Plane Plane { get; set; }

      /// <summary>
      /// Gets or sets the Plane id.
      /// </summary>
      public long PlaneId { get; set; }

      /// <summary>
      /// Gets or sets the Airport.
      /// </summary>
      public Airport Airport { get; set; }

      /// <summary>
      /// Gets or sets the Airport id.
      /// </summary>
      public int AirportId { get; set; }
  }

Transform the service

Use long as TKey type in the inheritance CrudAppServiceBase

  public class PlaneAppService : CrudAppServiceBase<PlaneDto, Plane, long, PagingFilterFormatDto, PlaneMapper>, IPlaneAppService

Transform the service interface

Use long as TKey type in the inheritance ICrudAppServiceBase

  public interface IPlaneAppService : ICrudAppServiceBase<PlaneDto, Plane, long, PagingFilterFormatDto>

Transform the controller

Use long in the list of ids in Remove function

      public async Task<IActionResult> Remove([FromQuery] List<long> ids)

Generate the migration

Add-Migration "PlaneLongId" -Context "DataContext"

Adapt the migration

Due to a known bug in ef5.0 you have to add manually the remove of the PrimaryKey and ForeignKey on each element modified, and recreate them after change in Up and Down function.

  public partial class PlaneLongId : Migration
  {
      protected override void Up(MigrationBuilder migrationBuilder)
      {
          // Begin Manually Added
          migrationBuilder.DropForeignKey(
              name: "FK_PlaneAirport_Planes_PlaneId",
              table: "PlaneAirport");
          migrationBuilder.DropPrimaryKey(
              name: "PK_Planes", 
              table: "Planes");
          migrationBuilder.DropPrimaryKey(
              name: "PK_PlaneAirport",
              table: "PlaneAirport");
          // End Manually Added

          migrationBuilder.AlterColumn<long>(
              name: "Id",
              table: "Planes",
              type: "bigint",
              nullable: false,
              oldClrType: typeof(int),
              oldType: "int")
              .Annotation("SqlServer:Identity", "1, 1")
              .OldAnnotation("SqlServer:Identity", "1, 1");

          migrationBuilder.AlterColumn<long>(
              name: "PlaneId",
              table: "PlaneAirport",
              type: "bigint",
              nullable: false,
              oldClrType: typeof(int),
              oldType: "int");

          // Begin Manually Added
          migrationBuilder.AddPrimaryKey(
              name: "PK_Planes",
              table: "Planes",
              column: "Id");
          migrationBuilder.AddForeignKey(
              name: "FK_PlaneAirport_Planes_PlaneId",
              table: "PlaneAirport",
              column: "PlaneId",
              principalTable: "Planes",
              principalColumn: "Id",
              onDelete: ReferentialAction.Cascade);
          migrationBuilder.AddPrimaryKey(
              name: "PK_PlaneAirport",
              table: "PlaneAirport",
              columns: new string[] {"PlaneId", "AirportId"});
          // End Manually Added
      }

      protected override void Down(MigrationBuilder migrationBuilder)
      {
          // Begin Manually Added
          migrationBuilder.DropForeignKey(
              name: "FK_PlaneAirport_Planes_PlaneId",
              table: "PlaneAirport");
          migrationBuilder.DropPrimaryKey(
              name: "PK_Planes",
              table: "Planes");
          migrationBuilder.DropPrimaryKey(
              name: "PK_PlaneAirport",
              table: "PlaneAirport");
          // End Manually Added

          migrationBuilder.AlterColumn<int>(
              name: "Id",
              table: "Planes",
              type: "int",
              nullable: false,
              oldClrType: typeof(long),
              oldType: "bigint")
              .Annotation("SqlServer:Identity", "1, 1")
              .OldAnnotation("SqlServer:Identity", "1, 1");

          migrationBuilder.AlterColumn<int>(
              name: "PlaneId",
              table: "PlaneAirport",
              type: "int",
              nullable: false,
              oldClrType: typeof(long),
              oldType: "bigint");

          // Begin Manually Added
          migrationBuilder.AddPrimaryKey(
              name: "PK_Planes",
              table: "Planes",
              column: "Id");
          migrationBuilder.AddForeignKey(
              name: "FK_PlaneAirport_Planes_PlaneId",
              table: "PlaneAirport",
              column: "PlaneId",
              principalTable: "Planes",
              principalColumn: "Id",
              onDelete: ReferentialAction.Cascade);
          migrationBuilder.AddPrimaryKey(
              name: "PK_PlaneAirport",
              table: "PlaneAirport",
              columns: new string[] { "PlaneId", "AirportId" });
          // End Manually Added
      }
  }

Migrate the base

Update-Database -Context "DataContext"