SQL Server009.Working with SQL Server LocalDB –【在sql server localdb 上操作数据】

Working with SQL Server LocalDB

以sql server localdb
上操作数据

2017-3-7 2 分钟阅读时长 

本文内容

1.SQL Server Express
LocalDB

SQL Server Express
LocalDB 
sql server 的一个简化免费版本

2.Seed the
database

初始化数据库的初始表数据

By Rick Anderson

The MvcMovieContext object handles the task of connecting to the
database and mapping Movie objects to database records.

MvcMovieContext
对象处理了链接数据库及照Movie 对象到说明记录之任务.

The database context is registered with the Dependency
Injection container
in the ConfigureServices method in the Startup.cs file:

DB上下文在Startup.cs
文件之ConfigureServices 方法吃被登记到了DI容器中:

SQL Server 1SQL Server 2

 1 public void ConfigureServices(IServiceCollection services)
 2 
 3 {
 4 
 5     // Add framework services.
 6 
 7     services.AddMvc();
 8 
 9  
10 
11     services.AddDbContext<MvcMovieContext>(options =>
12 
13             options.UseSqlServer(Configuration.GetConnectionString("MvcMovieContext")));
14 
15 }

C# code

The ASP.NET
Core Configuration system
reads the ConnectionString.

Asp.net core
的配置体系读取了ConnectionString 的配备的值。

For local development, it gets the connection string from
the appsettings.json file:

对本地开发,它于appsettings.json
文件获取链接字符串的值:

SQL Server 3SQL Server 4

1 "ConnectionStrings": {
2 
3   "MvcMovieContext": "Server=(localdb)\\mssqllocaldb;Database=MvcMovieContext-20613a4b-deb5-4145-b6cc-a5fd19afda13;Trusted_Connection=True;MultipleActiveResultSets=true"
4 
5 }

JSON Code

When you deploy the app to a test or production server, you can use an
environment variable or another approach to set the connection string to
a real SQL Server.

当您用使部署及一个测试或生育服务器,你得运用环境变量或另的方式来设置一个真的db链接字符串的价。

See Configuration for
more information.

查看Configuration
获取更多信息。

SQL Server Express LocalDB

(一个简化的免费的轻量的sql
server 版本)

LocalDB is a lightweight version of the SQL Server Express Database
Engine that is targeted for program development.

LocalDB 是 SQL Server Express
Database Engine 的一个轻量版本,目的是当地的程序支付。

LocalDB starts on demand and runs in user mode, so there is no complex
configuration.

LocalDB
因用户模式直接开始询问即可,因此并未复杂的安排。

By default, LocalDB database creates “*.mdf” files in
the C:/Users/<user> directory.

默认情况下,LocalDB
会在C:/Users/<user> 文件夹下开创”*.mdf” 数据库文件。

  • From the View menu, open SQL Server Object Explorer (SSOX).

View  菜单,打开 SQL
Server Object Explorer

SQL Server 5

  • Right click on the Movie table > View Designer

右击 Movie  表,点击  >
View Designer
菜单

SQL Server 6

SQL Server 7

Note the key icon next to ID. By default, EF will make a property
named ID the primary key.

只顾PK图标在ID
字段旁边,EF默认会采取ID做呢一个PK。

  • Right click on the Movie table > View Data

右击 Movie 表,选择 > View
Data
菜单

SQL Server 8

SQL Server 9

Seed the database

望数据库初始化值

Create a new class named SeedData in the Models folder. Replace the
generated code with the following:

Models
文件夹下新建一个誉为也SeedData
类,用脚的代码替换掉自动生成的代码:

SQL Server 10SQL Server 11

  1 using Microsoft.EntityFrameworkCore;
  2 
  3 using Microsoft.Extensions.DependencyInjection;
  4 
  5 using System;
  6 
  7 using System.Linq;
  8 
  9  
 10 
 11 namespace MvcMovie.Models
 12 
 13 {
 14 
 15     public static class SeedData
 16 
 17     {
 18 
 19         public static void Initialize(IServiceProvider serviceProvider)
 20 
 21         {
 22 
 23             using (var context = new MvcMovieContext(
 24 
 25                 serviceProvider.GetRequiredService<DbContextOptions<MvcMovieContext>>()))
 26 
 27             {
 28 
 29                 // Look for any movies.
 30 
 31                 if (context.Movie.Any())
 32 
 33                 {
 34 
 35                     return;   // DB has been seeded
 36 
 37                 }
 38 
 39  
 40 
 41                 context.Movie.AddRange(
 42 
 43                      new Movie
 44 
 45                      {
 46 
 47                          Title = "When Harry Met Sally",
 48 
 49                          ReleaseDate = DateTime.Parse("1989-1-11"),
 50 
 51                          Genre = "Romantic Comedy",
 52 
 53                          Price = 7.99M
 54 
 55                      },
 56 
 57  
 58 
 59                      new Movie
 60 
 61                      {
 62 
 63                          Title = "Ghostbusters ",
 64 
 65                          ReleaseDate = DateTime.Parse("1984-3-13"),
 66 
 67                          Genre = "Comedy",
 68 
 69                          Price = 8.99M
 70 
 71                      },
 72 
 73  
 74 
 75                      new Movie
 76 
 77                      {
 78 
 79                          Title = "Ghostbusters 2",
 80 
 81                          ReleaseDate = DateTime.Parse("1986-2-23"),
 82 
 83                          Genre = "Comedy",
 84 
 85                          Price = 9.99M
 86 
 87                      },
 88 
 89  
 90 
 91                    new Movie
 92 
 93                    {
 94 
 95                        Title = "Rio Bravo",
 96 
 97                        ReleaseDate = DateTime.Parse("1959-4-15"),
 98 
 99                        Genre = "Western",
100 
101                        Price = 3.99M
102 
103                    }
104 
105                 );
106 
107                 context.SaveChanges();
108 
109             }
110 
111         }
112 
113     }
114 
115 }

C# Code

If there are any movies in the DB, the seed initializer returns and no
movies are added.

如果数据库中发生数量记录,就会见直接回,如果无就会增长这些开数据。

SQL Server 12SQL Server 13

1 if (context.Movie.Any())
2 
3 {
4 
5     return;   // DB has been seeded.
6 
7 }

C# Code

Add the seed initializer to the end of the Configure method in
the Startup.cs file:

将多少初始化类添加到Startup.cs
文件之Configure  方法的末段一实施:

SQL Server 14SQL Server 15

 1             app.UseStaticFiles();
 2 
 3             app.UseMvc(routes =>
 4 
 5             {
 6 
 7                 routes.MapRoute(
 8 
 9                     name: "default",
10 
11                     template: "{controller=Home}/{action=Index}/{id?}");
12 
13             });
14 
15  
16 
17             SeedData.Initialize(app.ApplicationServices);
18 
19         }
20 
21     }
22 
23 }

C# Code

Test the app

测试用

  • Delete all the records in the DB. You can do this with the delete
    links in the browser or from SSOX.

若是抹db中的所有数据记录,你可在
SSOX 中点击删除链接即可。

  • Force the app to initialize (call the methods in the Startup class)
    so the seed method runs.

强制行使初始化,在 Startup 
类中seed 方法会被实践。

To force initialization, IIS Express must be stopped and restarted. You
can do this with any of the following approaches:

为强制初始化,iis express
必须再次开一下。你可采用以下方式的不论一种来成功:

  • Right click the IIS Express system tray icon in the notification
    area and tap Exit or Stop Site

右击系统托盘上通报区域的iis图标,并点击
Exit or Stop Site

SQL Server 16

SQL Server 17

  • If you were running VS in non-debug mode, press F5 to run in debug
    mode

一经你运行vs在不调试模式,按F5运行上调试模式

  • If you were running VS in debug mode, stop the debugger and press F5

如果您运行vs在调试模式,停止调试并依照下F5

The app shows the seeded data.

运展示有初始化后的多寡: 

SQL Server 18

 

 

 

 

                                         蒙

                                    2017-08-14
15:22 周一

 

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