using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
namespace MusicBank.Models
{
public class Artist
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public Guid Id { get; set; }
[Required]
public string Name { get; set; }
[Required]
public int Age { get; set; }
public virtual List
一个歌唱家,有个名字和年龄,然后有N个歌曲。
Audio
using System;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
namespace MusicBank.Models
{
public class Audio
{
[Key]
[DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
public Guid Id { get; set; }
[Required]
public string Name { get; set; }
[Required]
public int Type { get; set; }
[Required]
public string Src { get; set; }
[Required]
public Guid ArtistId { get; set; }
public Artist Artist { get; set; }
}
}
歌曲也简化了,一个名字,一个类型,一个源文件,属于某个歌唱家。
MusicContext
这个想必大家不陌生吧,用于数据库的查询等操作就全靠这个了;算是EF的精髓。
using Microsoft.Data.Entity;
namespace MusicBank.Models
{
public class MusicContext : DbContext
{
public DbSet
这里只需要添加两个表就OK。
SampleData
为了方便,这里我直接在创建数据库的时候就进行数据的初始化工作,添加一些默认数据。
using Microsoft.Framework.DependencyInjection;
using System;
using System.Linq;
namespace MusicBank.Models
{
public class SampleData
{
public static void Initialize(IServiceProvider serviceProvider)
{
var cOntext= serviceProvider.GetService();
if (context.Database.EnsureCreated())
{
if (!context.Artists.Any())
{
var austen = context.Artists.Add(
new Artist { Name = "Austen", Age = 21 }).Entity;
var dickens = context.Artists.Add(
new Artist { Name = "Dickens", Age = 25 }).Entity;
var cervantes = context.Artists.Add(
new Artist { Name = "Cervantes", Age = 27 }).Entity;
context.Audio.AddRange(
new Audio()
{
Name = "Pride",
Type = 1,
Artist = austen,
Src = "Pride.mp3"
},
new Audio()
{
Name = "Northanger",
Type = 2,
Artist = austen,
Src = "Northanger.mp3"
},
new Audio()
{
Name = "David",
Type = 3,
Artist = dickens,
Src = "David.mp3"
},
new Audio()
{
Name = "DonQuixote",
Type = 1,
Artist = cervantes,
Src = "DonQuixote.mp3"
}
);
context.SaveChanges();
}
}
}
}
}
using Microsoft.AspNet.Builder;
using Microsoft.AspNet.Hosting;
using Microsoft.Data.Entity;
using Microsoft.Dnx.Runtime;
using Microsoft.Framework.Configuration;
using Microsoft.Framework.DependencyInjection;
using MusicBank.Models;
namespace MusicBank
{
public class Startup
{
public Startup(IHostingEnvironment env, IApplicationEnvironment appEnv)
{
var builder = new ConfigurationBuilder(appEnv.ApplicationBasePath)
.AddJsonFile("config.json")
.AddJsonFile($"config.{env.EnvironmentName}.json", optional: true);
builder.AddEnvironmentVariables();
COnfiguration= builder.Build();
}
public IConfigurationRoot Configuration { get; set; }
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc();
services.AddEntityFramework()
.AddSqlServer()
.AddDbContext(optiOns=>
{
options.UseSqlServer(Configuration["Data:MusicConnection:ConnectionString"]);
});
}
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
app.UseStaticFiles();
app.UseMvc();
SampleData.Initialize(app.ApplicationServices);
}
}
}
到这里我们的初始化操作基本完成了,现在来看看如何访问数据库数据了。
Controllers
首先在根目录添加文件夹 Controllers,右键-添加-新建项
在这里我就使用一个简单的WebAPI来进行数据演示了,后面会在文章中详细写写数据的渲染相关。
在文件 AudioController.cs 中,我们更改代码为:
using Microsoft.AspNet.Mvc;
using MusicBank.Models;
using System.Collections.Generic;
using System.Linq;
namespace MusicBank.Controllers
{
[Route("api/[controller]")]
public class AudioController : Controller
{
[FromServices]
public MusicContext db { get; set; }
[HttpGet]
public IEnumerable
一个属性,两个方法。
在这里我们可以看见 MusicContext 属性并没有初始化,但是下面却能直接调用;这是因为我们添加了一个属性“[FromServices]”,该属性意味着服务器能自动采用注解的方式对 db 进行赋值。
下面两个方法分别返回全部的音乐列表,和根据音乐名称返回音乐相关信息。
当然在两个方法上都有“[HttpGet]”属性,该属性指定了请求类型为 Get 方式,当然也有其他几种,如:“HttpPost”“HttpPut”“HttpDelete”等。