通过迁移更新实体框架数据库

Question

I'm working on my ASP.NET MVC application with Entity Framework. After enabling migration and adding a migration like this:

public override void Up()
{
        DropForeignKey("dbo.PersonModel", "TeamModel_TeamId", "dbo.TeamModel");
        DropIndex("dbo.PersonModel", new[] { "TeamModel_TeamId" });
        RenameColumn(table: "dbo.PersonModel", name: "TeamModel_TeamId", newName: "TeamModelRefId");
        DropPrimaryKey("dbo.PersonModel");
        AddColumn("dbo.PersonModel", "IdPerson", c => c.Int(nullable: false, identity: true));
        AlterColumn("dbo.PersonModel", "TeamModelRefId", c => c.Int(nullable: false));
        AddPrimaryKey("dbo.PersonModel", "IdPerson");
        CreateIndex("dbo.PersonModel", "TeamModelRefId");
        AddForeignKey("dbo.PersonModel", "TeamModelRefId", "dbo.TeamModel", "TeamId", cascadeDelete: true);
        DropColumn("dbo.PersonModel", "PersonId");
}

public override void Down()
{
        AddColumn("dbo.PersonModel", "PersonId", c => c.Int(nullable: false, identity: true));
        DropForeignKey("dbo.PersonModel", "TeamModelRefId", "dbo.TeamModel");
        DropIndex("dbo.PersonModel", new[] { "TeamModelRefId" });
        DropPrimaryKey("dbo.PersonModel");
        AlterColumn("dbo.PersonModel", "TeamModelRefId", c => c.Int());
        DropColumn("dbo.PersonModel", "IdPerson");
        AddPrimaryKey("dbo.PersonModel", "PersonId");
        RenameColumn(table: "dbo.PersonModel", name: "TeamModelRefId", newName: "TeamModel_TeamId");
        CreateIndex("dbo.PersonModel", "TeamModel_TeamId");
        AddForeignKey("dbo.PersonModel", "TeamModel_TeamId", "dbo.TeamModel", "TeamId");
}

I get an error like this:

Error Number:2744,State:2,Class:16
Multiple identity columns specified for table 'PersonModel'. Only one identity column per table is allowed.

This is my model:

public class PersonModel
{
    [Key]
    public int IdPerson { get; set; }
    public string NickName { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string Email { get; set; }

    public int TeamModelRefId { get; set; }

    [ForeignKey("TeamModelRefId")]    
    public virtual TeamModel TeamModel { get; set; }
}

public class TeamModel
{
    public TeamModel()
    {
        TeamMembers = new List<PersonModel>();
        this.Tournaments = new HashSet<TournamentModel>();
    }

    [Key]
    public int TeamId { get; set; }

    public string TeamName { get; set; }

    public virtual ICollection<PersonModel> TeamMembers { get; set; }

    public ICollection<TournamentModel> Tournaments { get; set; }

    public virtual MatchUpEntryModel MatchupEntry { get; set; }

    public virtual MatchUpModel Matchup { get; set; }
}

Answer 1

Looks like you've changed your primary key column from PersonId to IdPerson . The error is being thrown because the latter is added before the former is removed. Rearrange your Up() method like so:

public override void Up()
    {
        DropForeignKey("dbo.PersonModel", "TeamModel_TeamId", "dbo.TeamModel");
        DropIndex("dbo.PersonModel", new[] { "TeamModel_TeamId" });
        RenameColumn(table: "dbo.PersonModel", name: "TeamModel_TeamId", newName: "TeamModelRefId");
        DropPrimaryKey("dbo.PersonModel");
        AddPrimaryKey("dbo.PersonModel", "IdPerson");
        CreateIndex("dbo.PersonModel", "TeamModelRefId");
        AddForeignKey("dbo.PersonModel", "TeamModelRefId", "dbo.TeamModel", "TeamId", cascadeDelete: true);
        DropColumn("dbo.PersonModel", "PersonId");
        AddColumn("dbo.PersonModel", "IdPerson", c => c.Int(nullable: false, identity: true));
        AlterColumn("dbo.PersonModel", "TeamModelRefId", c => c.Int(nullable: false));
    }