.net - 如何在 EF CF 中设置 POCO 的默认值？

Question

在 Entity Framework 代码优先方法中，如何为 POCO 的 EntityConfiguration 类中的属性设置默认值？

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 ?
    }
}

Answer 1

随着 Entity Framework 4.3 的发布，您可以通过迁移来完成此操作。

EF 4.3 Code First Migrations Walkthrough

所以使用你的例子，它会是这样的:

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
    }
}