asp.net-wingtip学习之创建数据访问层

一. 什么是数据访问层
在wingtip项目中，数据访问层是对以下三者的总称：
1. product类等数据相关的类(class)
2. 数据库和存储类成员的数据表(database)
3. 上述二者的交互操作。

product类：

 1 using System.ComponentModel.DataAnnotations;
 2
 3 namespace WingtipToys.Models
 4 {
 5   public class Product
 6   {
 7     [ScaffoldColumn(false)]
 8     public int ProductID { get; set; }
 9
10     [Required, StringLength(100), Display(Name = "Name")]
11     public string ProductName { get; set; }
12
13     [Required, StringLength(10000), Display(Name = "Product Description"), DataType(DataType.MultilineText)]
14     public string Description { get; set; }
15
16     public string ImagePath { get; set; }
17
18     [Display(Name = "Price")]
19     public double? UnitPrice { get; set; }
20
21     public int? CategoryID { get; set; }
22
23     public virtual Category Category { get; set; }
24   }
25 }

database(T-SQL)：

 1 CREATE TABLE [dbo].[Products] (
 2     [ProductID]   INT            IDENTITY (1, 1) NOT NULL,
 3     [ProductName] NVARCHAR (100) NOT NULL,
 4     [Description] NVARCHAR (MAX) NOT NULL,
 5     [ImagePath]   NVARCHAR (MAX) NULL,
 6     [UnitPrice]   FLOAT (53)     NULL,
 7     [CategoryID]  INT            NULL,
 8     CONSTRAINT [PK_dbo.Products] PRIMARY KEY CLUSTERED ([ProductID] ASC),
 9     CONSTRAINT [FK_dbo.Products_dbo.Categories_CategoryID] FOREIGN KEY ([CategoryID]) REFERENCES [dbo].[Categories] ([CategoryID])
10 );
11
12
13 GO
14 CREATE NONCLUSTERED INDEX [IX_CategoryID]
15     ON [dbo].[Products]([CategoryID] ASC);

原文地址：https://www.cnblogs.com/codingcz/p/9501574.html