EF Core 中的种子数据

种子数据：迁移数据库时的初始数据。
播种：EF Core 2.1+ 支持的创建初始数据的方法。

推荐通过扩展方法，将创建种子数据的方法与 DbContext 解耦：

public class AppDbContext : DbContext
{
    public AppDbContext(DbContextOptions options) : base(options)
    {
    }
    public DbSet<Student> Students { get; set; }
    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        modelBuilder.Seed();
    }
}

public static class ModelBuilderExtensions
{
    public static void Seed(this ModelBuilder modelBuilder)
    {
        modelBuilder.Entity<Student>().HasData(
            new Student
            {
                Id = 1,
                Name = "ltm",
                ClassName = ClassNameEnum.FirstGrade,
                Email = "ltm@ddxc.org"
            },
            new Student
            {
                Id = 2,
                Name = "角落的白板报",
                ClassName = ClassNameEnum.GradeThree,
                Email = "werltm@qq.com"
            });
    }
}