相关疑难解决方法(0)

如何限制UserName表格中的字段AspNetUsers？

这不是:

public class ApplicationUser : IdentityUser
{
    [Required, MaxLength(15)]
    public string UserName { get; set; }

}

或这个:

modelBuilder.Entity<ApplicationUser>().Property(x => x.UserName).HasMaxLength(15);

作品.

我需要这个,因为设置了Index上nvarchar(max)给了我这个错误信息:

表'dbo.AspNetUsers'中的列'UserName'的类型无效,无法用作索引中的键列.

为了详细,我试图设置这样的索引:

public override void Up()
{
    CreateIndex("dbo.AspNetUsers", "UserName", true, "IX_UserName");
}

public override void Down()
{
    DropIndex("dbo.AspNetUsers", "IX_UserName");
}

我刚刚将库Microsoft.AspNet.Identity.EntityFramework更新到最后一个版本(2.0.0.0),我发现创建表时出现了一些错误.当我生成迁移代码(向上和向下方法)时,我无法将更改上传到数据库,因为我在执行"Updata-Database"时遇到索引问题

指定密钥太长; 最大密钥长度为767字节

要执行的代码:

public override void Up()
    {
        CreateTable(
            "dbo.AspNetRoles",
            c => new
                {
                    Id = c.String(nullable: false, maxLength: 128, storeType: "nvarchar"),
                    Name = c.String(nullable: false, maxLength: 256, storeType: "nvarchar"),
                })
            .PrimaryKey(t => t.Id)
            .Index(t => t.Name, unique: true, name: "RoleNameIndex");

        CreateTable(
            "dbo.AspNetUserRoles",
            c => new
                {
                    UserId = c.String(nullable: false, maxLength: 128, storeType: "nvarchar"),
                    RoleId = c.String(nullable: false, maxLength: 128, storeType: "nvarchar"),
                })
            .PrimaryKey(t => new { t.UserId, t.RoleId })
            .ForeignKey("dbo.AspNetRoles", t => t.RoleId, cascadeDelete: true)
            .ForeignKey("dbo.AspNetUsers", t …