.NET Core 2.1中的更新迁移

Question

While update-migration I get the error "To change the IDENTITY property of a column, the column needs to be dropped and recreated." wite .NET Core 2.1

CarModel

    public int Id { get; set; }
    public string VIN { get; set; }
    public string Make { get; set; }
    public string Model { get; set; }
    public string Style { get; set; }
    public int Year { get; set; }
    public double Miles { get; set; }
    public string Color { get; set; }

    public string UserId { get; set; }
    [ForeignKey("UserID")]
    public virtual ApplicationUser ApplicationUser { get; set; }

Migration that I get

public partial class AddCarToDb : Migration
{
    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.CreateTable(
            name: "Cars",
            columns: table => new
            {
                Id = table.Column<int>(nullable: false)
                    .Annotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn),
                VIN = table.Column<string>(nullable: true),
                Make = table.Column<string>(nullable: true),
                Model = table.Column<string>(nullable: true),
                Style = table.Column<string>(nullable: true),
                Year = table.Column<int>(nullable: false),
                Miles = table.Column<double>(nullable: false),
                Color = table.Column<string>(nullable: true),
                UserId = table.Column<string>(nullable: true),
                UserID = table.Column<string>(nullable: true)
            },
            constraints: table =>
            {
                table.PrimaryKey("PK_Cars", x => x.Id);
                table.ForeignKey(
                    name: "FK_Cars_AspNetUsers_UserID",
                    column: x => x.UserID,
                    principalTable: "AspNetUsers",
                    principalColumn: "Id",
                    onDelete: ReferentialAction.Restrict);
            });

        migrationBuilder.CreateIndex(
            name: "IX_Cars_UserID",
            table: "Cars",
            column: "UserID");
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropTable(
            name: "Cars");
    }
}

I try to create Car table in my database, but after I use update-migration I get that error

Answer 1

After some research, I see some link to solve this issue. You can try this, if not please let me know and I would love to support you.

https://thisworksonmymachine.com/2017/02/13/ef-core-the-setup-part-4/

https://github.com/aspnet/EntityFrameworkCore/issues/329

Cheers

Answer 2

I have solved this problem by creating the new project with Dot Net core 2.0 and it works fine. I think the problem is because I try to upgrade from 2.0 to be 2.1.1 after I upgrade everything is broke. Thank you for all answer

Answer 3

在您的解决方案中删除“迁移文件夹”，打开包管理器控制台并输入：

Add-Migration initial