为什么 EF Core 2.2 总是更新“AspNetUsers”表中的“ConcurrencyStamp”、“PasswordHash”？

Question

我有 .net core 应用程序，它使用 ef core 2.2 代码优先模型，当我运行时

添加迁移

它总是更新表"ConcurrencyStamp", "PasswordHash"中的列值"AspNetUsers"。

自动生成的UP方法内容是

        migrationBuilder.UpdateData(
            table: "AspNetUsers",
            keyColumn: "Id",
            keyValue: new Guid("b0bea27d-5eae-4836-8f85-8bf8f1aed8d5"),
            columns: new[] { "ConcurrencyStamp", "PasswordHash" },
            values: new object[] { "c599b745-8e24-438b-bd62-8264102ac960", "AQAAAAEAACcQAAAAEHjqRSJuPQtzpQR7L7hUNo3vFM8P9dhHkiXQjYRpdgS1Z9I9TXQ2XwhM9CQiE0oVyg==" });

        migrationBuilder.UpdateData(
            table: "AspNetUsers",
            keyColumn: "Id",
            keyValue: new Guid("b0bea27d-5eae-4836-8f85-8bf8f1aed8d6"),
            columns: new[] { "ConcurrencyStamp", "PasswordHash" },
            values: new object[] { "bdbc0bcf-6eaa-489b-b2a2-9c1742a38bf4", "AQAAAAEAACcQAAAAEBpVzPQl74gxL+V93biLDmn4oKNJSZZ5VDUpwSQ/S8h+itGvGbScqG78Wi35bmN4dQ==" });

我的OnModelCreating方法如下

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    base.OnModelCreating(modelBuilder);

    modelBuilder.ApplyConfigurations(
        typeof(SampleDBContext).Assembly,
        typeof(IEntityTypeConfiguration<>));

    DatabaseSeeder.Seed(modelBuilder);
}

在种子方法内部，我调用种子应用程序用户的方法。

    private static void SeedApplicationUser(ModelBuilder modelBuilder)
    {
        var hasher = new PasswordHasher<ApplicationUser>();

        var admin = new ApplicationUser
        {
            Id = Guid.Parse("b0bea27d-5eae-4836-8f85-8bf8f1aed8d4"),
            RoleType = RoleTypes.Admin,
            Email = "admin@gmail.io",
            NormalizedEmail = "ADMIN@GMAIL.IO",
            EmailConfirmed = true,
            UserName = "admin",
            NormalizedUserName = "ADMIN",
        };

        var user1 = new ApplicationUser
        {
            Id = Guid.Parse("b0bea27d-5eae-4836-8f85-8bf8f1aed8d5"),
            RoleType = RoleTypes.User,
            Email = "user1@gmail.io",
            NormalizedEmail = "USER1@GMAIL.IO",
            EmailConfirmed = true,
            UserName = "user1",
            AccessFailedCount = 0,
            NormalizedUserName = "USER1",
        };

        var user2 = new ApplicationUser
        {
            Id = Guid.Parse("b0bea27d-5eae-4836-8f85-8bf8f1aed8d6"),
            RoleType = RoleTypes.User,
            Email = "user2@gmail.io",
            NormalizedEmail = "USER2@GMAIL.IO",
            EmailConfirmed = true,
            UserName = "user2",
            AccessFailedCount = 0,
            NormalizedUserName = "USER2",
        };

        admin.PasswordHash = hasher.HashPassword(admin, "admin@23");
        user1.PasswordHash = hasher.HashPassword(user1, "user1@23");
        user2.PasswordHash = hasher.HashPassword(user2, "user2@23");

        modelBuilder.Entity<ApplicationUser>()
            .HasData(admin, user1, user2);
    }

这是正常行为还是我错过了什么？

如果有人需要更多详细信息，请评论。我不知道该提供什么。

谢谢，

Answer 1

ConcurrencyStamp总是在创建新对象时生成。

public virtual string ConcurrencyStamp { get; set; } = Guid.NewGuid().ToString();

同样是关于PasswordHash. 它的值始终在您的种子中重新生成，并且始终不同（即使对于相同的密码）。

这就是为什么 EF Core 会看到数据库中的数据与种子数据之间的差异。每次创建新迁移时，这两个字段的值都不同。

快速的解决方法（但不是最好的）是始终使用相同的硬编码哈希和并发标记，但这确实是错误的。

使用自定义初始化逻辑会更好，这在这个问题中得到了很好的描述：How to see an Admin user in EF Core 2.1.0?