如何使用EF6 for Web API为域模型创建可选的日志记录属性？

Question

I am designing an Web API where I'd like to keep track of the User who created, updated or removed a certain entity with the corresponding methods.

Usage

• GET --> Nothing
• POST --> Created
• PUT --> Created AND Modified
• DELETE --> Removed

So you can say Created is mandatory and the Modified + Removed are optional.

Entities:

public User {
    public int Id { get; set; }
    public int FirstName { get; set; }
    public int LastName { get; set; }
}

public MyRandomEntity {
    public int Id { get; set; }

    // ...

    public DateTime CreatedDate { get; private set; } //mandatory
    public User CreatedBy { get; private set; } //mandatory

    public DateTime UpdatedDate { get; set; } //optional
    public User UpdatedBy { get; set; } //optional

    public DateTime RemovedAt { get; set; } //optional
    public User RemovedBy { get; set; } //optional
}

I am kinda struggling to get this right. Complex types cannot be optional by default plus I am using three foreign keys in this model.

Is there a way to configure this nicely using FluentApi? I'd like to point out there is no other entity that requires these same logging properties as I call them.

Thanks in advance

Answer 1

In EF all fields are required if you don't specify that they are nullable. Not manditory fields are nullable types example:

public MyRandomEntity {
    public int Id { get; set; }

    // ...

    public DateTime CreatedDate { get; private set; } //mandatory
    public User CreatedBy { get; private set; } //mandatory

    public DateTime? UpdatedDate { get; set; } //optional
    public User? UpdatedBy { get; set; } //optional

    public DateTime? RemovedAt { get; set; } //optional
    public User? RemovedBy { get; set; } //optional
}