ASP.NET Core (Database First)

CREATE DATABASE [EFCore_dbfirst]
GO

USE [EFCore_dbfirst]
GO

CREATE TABLE [Blog] (
    [BlogId] int NOT NULL IDENTITY,
    [Url] nvarchar(max) NOT NULL,
    CONSTRAINT [PK_Blog] PRIMARY KEY ([BlogId])
);
GO

CREATE TABLE [Post] (
    [PostId] int NOT NULL IDENTITY,
    [BlogId] int NOT NULL,
    [Content] nvarchar(max),
    [Title] nvarchar(max),
    CONSTRAINT [PK_Post] PRIMARY KEY ([PostId]),
    CONSTRAINT [FK_Post_Blog_BlogId] FOREIGN KEY ([BlogId]) REFERENCES [Blog] ([BlogId]) ON DELETE CASCADE
);
GO

INSERT INTO [Blog] (Url) VALUES
('http://blogs.msdn.com/dotnet'),
('http://blogs.msdn.com/webdev'),
('http://blogs.msdn.com/visualstudio')
GO

先创建数据库

创建一个新项目

这里我们选择  ASP.NET Core Web Application (.NET Core) 

这里选择Web 应用程序，然后更改身份验证 改为 不进行身份验证

添加包

工具‣的NuGet包管理器‣包管理器控制台

• Run Install-Package Microsoft.EntityFrameworkCore
• Run Install-Package Microsoft.EntityFrameworkCore.SqlServer

• Run Install-Package Microsoft.EntityFrameworkCore.Tools –Pre
• Run Install-Package Microsoft.EntityFrameworkCore.SqlServer.Design

引用好以后我们在project.json -> tools 节点加上 "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final"

"tools": {
        "Microsoft.EntityFrameworkCore.Tools": "1.0.0-preview2-final",
        "BundlerMinifier.Core": "2.0.238",
        "Microsoft.AspNetCore.Razor.Tools": "1.0.0-preview2-final",
        "Microsoft.AspNetCore.Server.IISIntegration.Tools": "1.0.0-preview2-final"
    },

根据数据库生成EF

还是使用程序包管理控制台

执行

 Scaffold-DbContext  "Data Source=.;Initial Catalog=EFCore_dbfirst;User ID=sa;Password=sa.123" Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models

分析一下这条命令

　　 Scaffold-DbContext 命令名称  +"数据库连接字符串"  + Microsoft.EntityFrameworkCore.SqlServer -OutputDir Models      ( 这貌似是Provider参数)

注意
运行以下命令来创建从现有数据库的模型。如果您收到一个错误， ‘Scaffold-DbContext’ is not recognized as the name of a cmdlet ，请重新打开Visual Studio中。

执行成功后生成了如下代码

注册与依赖注入上下文（Register your context with dependency injection）

在ASP.NET Core，配置通常在 Startup.cs。为了符合这种模式，我们将移动数据库配置 到Startup.cs中。

EFCore_dbfirstContext 中

删除如下代码

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            //#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(@"Data Source=.;Initial Catalog=EFCore_dbfirst;User ID=sa;Password=sa.123");
        }

添加如下代码

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

在 Startup.cs中  的 ConfigureServices方法 增加代码

这是增加后的效果

   // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddDbContext<EFCore_dbfirstContext>(options =>
                options.UseSqlServer("Data Source =.; Initial Catalog = EFCore_dbfirst; User ID = sa; Password = sa.123"));

            // Add framework services.
            services.AddMvc();
        }

开始写代码

添加 BlogsController

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using EFCoreDbFirst.Models;

// For more information on enabling MVC for empty projects, visit http://go.microsoft.com/fwlink/?LinkID=397860

namespace EFCoreDbFirst.Controllers
{
    public class BlogsController : Controller
    {
        private EFCore_dbfirstContext _context;

        public BlogsController(EFCore_dbfirstContext context)
        {
            _context = context;
        }

        public IActionResult Index()
        {
            return View(_context.Blog.ToList());
        }

        public IActionResult Create()
        {
            return View();
        }

        [HttpPost]
        [ValidateAntiForgeryToken]
        public IActionResult Create(Blog blog)
        {
            if (ModelState.IsValid)
            {
                _context.Blog.Add(blog);
                _context.SaveChanges();
                return RedirectToAction("Index");
            }

            return View(blog);
        }
    }
}

BlogsController

添加 Index.cshtml

@model IEnumerable<EFCoreDbFirst.Models.Blog>

@{
    ViewBag.Title = "Blogs";
}

<h2>Blogs</h2>

<p>
    <a asp-controller="Blogs" asp-action="Create">Create New</a>
</p>

<table class="table">
    <tr>
        <th>Id</th>
        <th>Url</th>
    </tr>

    @foreach (var item in Model)
    {
        <tr>
            <td>
                @Html.DisplayFor(modelItem => item.BlogId)
            </td>
            <td>
                @Html.DisplayFor(modelItem => item.Url)
            </td>
        </tr>
    }
</table>

Index.cshtml

添加 Create.cshtml

@model  EFCoreDbFirst.Models.Blog

@{
    ViewBag.Title = "New Blog";
}

<h2>@ViewData["Title"]</h2>

<form asp-controller="Blogs" asp-action="Create" method="post" class="form-horizontal" role="form">
    <div class="form-horizontal">
        <div asp-validation-summary="All" class="text-danger"></div>
        <div class="form-group">
            <label asp-for="Url" class="col-md-2 control-label"></label>
            <div class="col-md-10">
                <input asp-for="Url" class="form-control" />
                <span asp-validation-for="Url" class="text-danger"></span>
            </div>
        </div>
        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
</form>

Create.cshtml

来看看效果