1     public class ProductMap : EntityTypeConfiguration<Product>
2     {
3         public ProductMap()
4         {
5             ToTable("Product"); //指定表明
6             HasKey(p => p.Id);  //指定主键
7         }
8     }

1     public class Product
2     {
3         public int Id { get; set; }
4         public string Name { get; set; }
5         public string Description { get; set; }
6     }

1     public class ProductMap : EntityTypeConfiguration<Product>
2     {
3         public ProductMap()
4         {
5             ToTable("Product"); //指定表明
6             HasKey(p => p.Id);  //指定主键
7             Property(p => p.Name).IsRequired().HasMaxLength(200);
8         }
9     }

 1     internal sealed class Configuration : DbMigrationsConfiguration<MigrationOpt.Models.EntityContext>
 2     {
 3         public Configuration()
 4         {
 5             AutomaticMigrationsEnabled = false;
 6             ContextKey = "MigrationOpt.Models.EntityContext";
 7         }
 8
 9         protected override void Seed(MigrationOpt.Models.EntityContext context)
10         {
11
12         }
13     }

1 protected override void Seed(SchoolContext context)
2 {
3     context.Set<Student>().AddOrUpdate(
4       p => p.StudentName,
5       new Student { StudentName = "张三" },
6       new Student { StudentName = "李四" },
7       new Student { StudentName = "王五" }
8     );
9 }

1         public EntityContext()
2             : base("name=DBConnectionString")
3         {
4             Database.SetInitializer(new MigrateDatabaseToLatestVersion<EntityContext, Configuration>("DBConnectionString"));
5         }

 1     public partial class ChangeSet1 : DbMigration
 2     {
 3         public override void Up()
 4         {
 5             AlterColumn("dbo.Product", "Name", c => c.String(nullable: false, maxLength: 200));
 6         }
 7
 8         public override void Down()
 9         {
10             AlterColumn("dbo.Product", "Name", c => c.String());
11         }
12     }