实体框架7 IDENTITY_INSERT [英] Entity Framework 7 IDENTITY_INSERT

问题描述

我需要大量的用户数据的存储在每个用户已经拥有的ID作为密钥的数据库。但是，这些用户都出用户的一个较大的池，因此，该ID不增加，并且不能自动生成。我需要能够手动设置的ID。

I need to store a large amount of user data in a database where every user already has an ID as a key. However, these users all out of a larger pool of users, therefore, the ID does not increment and cannot be automatically generated. I need to be able to manually set the ID.

有一个简单的方法来做到这一点？

Is there an easy way to do this?

推荐答案

我做了一些测试，这似乎为我工作的EF 7.0.0 RC1决赛：

I've made some tests and this seems to work for me on EF 7.0.0 rc1-final:

modelBuilder.Entity<Foo>().HasKey(x => x.Id);
modelBuilder.Entity<Foo>().Property(x => x.Id).ValueGeneratedNever();    

我的测试代码：

My test code:

static void Main(string[] args)
{
    using (var db = new FooContext())
    {
        var myFoo = new Foo {Id = 1002, Descr = "Test"};
        db.Add(myFoo);
        db.SaveChanges();
    }
    using (var db = new FooContext())
    {
        var myFoo = db.Foos.FirstOrDefault(x => x.Id == 1002);
        Console.WriteLine($"id = {myFoo?.Id}, descrip = {myFoo?.Descr}");
    }
}

（完整的程序代码在这里：的 http://pastebin.com/hSs9HZCP ）

它正确地插入和检索与指定的id和表中的记录有指定了正确的主键

It correctly inserts and retrieves a record with the specified id and the table has the correct primary key specified.

这是生成的迁移代码：

migrationBuilder.CreateTable(
    name: "Foo",
    columns: table => new
    {
        Id = table.Column<long>(nullable: false),
        Descr = table.Column<string>(nullable: true)
    },
    constraints: table =>
    {
        table.PrimaryKey("PK_Foo", x => x.Id);
    });

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