Yes, you can't do this. You have to set the default in code. There's no real way around this.
More discussion about this here:
有一个答案要求添加[DatabaseGenerated(DatabaseGeneratedOption.Identity)]
加完之后,发现没有啥用
public class SomeTable{ ... [DatabaseGenerated(DatabaseGeneratedOption.Identity)] public DateTime CreatedDate { get; set; } ...}
结论:
这种有默认值的,只能通过自己在代码中设置对应实体的初始值,数据库的约束不起作用