c# - Entity Framework 6 : The INSERT statement conflicted with the FOREIGN KEY constraint Error but the parent record has been saved

Question

我的数据库中有两个表，Users 和 JobSeekerEmploymentDetails。

Users
---------------------------
ID        int (Auto Generated Primary Key)
Col1      ...

JobSeekerEmploymentDetails
---------------------------
ID        int (Auto Generated Primary Key)
Col1      ...
UserId    int (Foreign Key to Users table)

要在上面的表中插入记录，我的代码如下:(我使用的是EntityFramework 6和AutoMapper)

    public async Task<int> SaveJobSeeker(AccountInfoViewModel accountInfo, PersonalDetailViewModel personalDetail, EmploymentDetailsViewModel employmentDetails)
    {
        //create EF User object
        var user = new User {CreatedOn = DateTime.Now};

        //map data from the ViewModels into user class
        Mapper.Map(accountInfo, user);
        Mapper.Map(personalDetail, user);

        using (var db = new ITWebEntities())
        {
            //save user
            db.Users.Add(user);
            await db.SaveChangesAsync();

            //Create new EF class object and set recently saved user Id as foreign key value
            var jobSeekerEmpDetail = new JobSeekerEmploymentDetail { UserId = user.ID };

            //Map other detail from the ViewModel object           
            Mapper.Map(employmentDetails, jobSeekerEmpDetail);

            //save emp details info
            db.JobSeekerEmploymentDetails.Add(jobSeekerEmpDetail);
            return await db.SaveChangesAsync();
        }
    }

现在 User 已保存到数据库中，我可以看到 ID 的值已从保存的 User 对象中成功检索。但是最后一个 db.SaveChangesAsync() 语句抛出以下异常。

The INSERT statement conflicted with the FOREIGN KEY constraint "FK_EmploymentDetails_Users". The conflict occurred in database "ITWeb", table "dbo.Users", column 'ID'.
The statement has been terminated.

如以下屏幕截图所示，约束已正确设置:

我想我正在做一些愚蠢的事情，但我无法弄明白。你能帮忙吗？

Answer 1

这很简单。 Mapper.Map(employmentDetails, jobSeekerEmpDetail); 行实际上会将 UserId 覆盖为我在上一步中正确设置的 0。在执行映射并且它起作用后，我更改了代码以设置 UserId。

public async Task<int> SaveJobSeeker(AccountInfoViewModel accountInfo, PersonalDetailViewModel personalDetail, EmploymentDetailsViewModel employmentDetails)
{
    //create EF User object
    var user = new User {CreatedOn = DateTime.Now};

    //map data from the ViewModels into user class
    Mapper.Map(accountInfo, user);
    Mapper.Map(personalDetail, user);

    using (var db = new ITWebEntities())
    {
        //save user
        db.Users.Add(user);
        await db.SaveChangesAsync();

        //Create new EF class object and set recently saved user Id as foreign key value
        var jobSeekerEmpDetail = new JobSeekerEmploymentDetail();

        //Map other detail from the ViewModel object           
        Mapper.Map(employmentDetails, jobSeekerEmpDetail);

        jobSeekerEmpDetail.UserId = user.ID;

        //save emp details info
        db.JobSeekerEmploymentDetails.Add(jobSeekerEmpDetail);
        return await db.SaveChangesAsync();
    }
}