如何在 EF CF 中为 POCO 设置默认值? [英] How to set default value for POCO's in EF CF?

问题描述

在实体框架代码优先方法中，如何为 POCO 的 EntityConfiguration 类中的属性设置默认值?

In Entity Framework Code First approach, how do you set a default value for a property in the POCO's EntityConfiguration class?

public class Person
{
    public int Id { get; set; }
    public string Name { get; set; }
    public DateTime CreatedOn { get; set; }
}

public class PersonConfiguration : EntityConfiguration<Person>
{
    public PersonConfiguration()
    {
        Property(p => p.Id).IsIdentity();
        Property(p => p.Name).HasMaxLength(100);

        //set default value for CreatedOn ?
    }
}

推荐答案

随着 Entity Framework 4.3 的发布，您可以通过迁移来做到这一点.

With the release of Entity Framework 4.3 you can do this through Migrations.

EF 4.3 代码第一次迁移演练

所以使用你的例子，它会是这样的:

So using your example it would be something like:

public partial class AddPersonClass : DbMigration
{
    public override void Up()
    {
        CreateTable(
            "People",
            c => new
                {
                    Id = c.Int(nullable: false, identity: true),
                    Name = c.String(maxLength: 100),
                    CreatedOn = c.DateTime(nullable: false, defaultValue: DateTime.UtcNow)
                })
            .PrimaryKey(t => t.Id);
    }

    public overide void Down()
    {
        // Commands for when Migration is brought down
    }
}

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