EntityFrameworkCore操作记录

Install-Package Microsoft.VisualStudio.Web.CodeGeneration.Design -Version 2.0.3
Add-Migration Init
Update-Database Init

Install-Package 命令安装运行基架引擎所需的工具。

Add-Migration 命令生成用于创建初始数据库架构的代码。 此架构以（Models/MovieContext.cs 文件中的）DbContext 中指定的模型为基础。 Init 参数用于为迁移命名。 可以使用任意名称，但是按照惯例应选择描述迁移的名称。 有关详细信息，请参阅迁移简介。

Update-Database 命令在用于创建数据库的 Migrations/{time-stamp}_InitialCreate.cs 文件中运行 Up 方法。

    public partial class Blog
    {
        public Blog()
        {
            Post = new HashSet<Post>();
        }

        public int BlogId { get; set; }
        public string Url { get; set; }

        public ICollection<Post> Post { get; set; }
    }

 public partial class Post
    {
        public int PostId { get; set; }
        public int BlogId { get; set; }
        public string Content { get; set; }
        public string Title { get; set; }

        public Blog Blog { get; set; }
    }

    public partial class BloggingContext : DbContext
    {
        public BloggingContext()
        {
        }

        public BloggingContext(DbContextOptions<BloggingContext> options)
            : base(options)
        {
        }

        public virtual DbSet<Blog> Blog { get; set; }
        public virtual DbSet<Post> Post { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            if (!optionsBuilder.IsConfigured)
            {
                //warning To protect potentially sensitive information in your connection string, you should move it out of source code. See http://go.microsoft.com/fwlink/?LinkId=723263 for guidance on storing connection strings.
                optionsBuilder.UseSqlServer("Server=(localdb)\\mssqllocaldb;Database=Blogging;Trusted_Connection=True;");
            }
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Blog>(entity =>
            {
                entity.Property(e => e.Url).IsRequired();
            });

            modelBuilder.Entity<Post>(entity =>
            {
                entity.HasOne(d => d.Blog)
                    .WithMany(p => p.Post)
                    .HasForeignKey(d => d.BlogId);
            });
        }
    }