无法在Entity Framework中使用AddRange自动生成IDENTITY

Question

我不知道它是实体框架的设计选择还是代表我的错误方法,但每当我尝试将AddRange实体添加到DbSet时,我似乎无法获得自动生成的IDENTITY字段.

[Table("entities")]
public class Entity 
{
    [Key]
    [Column("id")]
    public long Id { get; set; }

    [Column("field")]
    public string Field { get; set; }
}

var entities = new Entity[] 
{
    new Entity() { Field = "A" },
    new Entity() { Field = "B" },
};

_dbContext.Entities.AddRange(entities);
await _dbContext.SaveChangesAsync();

//ids are still default(long) at this point!!

编辑: 这是更新的代码,以显示导致问题的原因:枚举.无需向实体类添加其他属性.

public class Request
{
    public string Field { get; set; }

    public Entity ToEntity()
    {
        return new Entity() { Field = Field };
    }
}

public async Task<IEnumerable<long>> SaveRequests(IEnumerable<Request> requests)
{
    var entities = requests.Select(r => r.ToEntity()); //not working
    var entities = requests.Select(r => r.ToEntity()).ToArray(); //working

    _dbContext.Entities.AddRange(entities);
    await _dbContext.SaveChangesAsync();

    return entities.Select(e => e.Id);
}

Answer 1

是什么导致了这个问题？可枚举!请查看我的问题中的EDIT部分以获得解决方案.