ASP.NET MVC+LINQ开发一个图书销售站点(6):创建数据层

1. 我们在Model下存放我们系统需要的数据，首先我们创建一个数据库的Linq to Sql Class

2.选中所有的表到设计视图

3. 新建一个BookShopDBDataContext的分布类，我们在这里写一些方法和逻辑层Controller交互.

using System;
using System.Data;
using System.Configuration;
using System.Linq;
using System.Xml.Linq;
using System.Collections.Generic;

namespace BookShop.Models
{
    public partial class BookShopDBDataContext
    {
        //return all categories       
        public List<Category> GetAllCategory()
        {
            return Categories.ToList();
        }

        //Add Category
        public void AddCategory(Category c)
        {
            
            this.Categories.InsertOnSubmit(c);
            this.SubmitChanges();
        }

        //Edit Category
        public void EditCategory(Category c)
        {
            
            this.UpdateCategory(c);
            this.SubmitChanges();
        }

        public Category GetCategory(int id)
        {
            return Categories.Single(c => c.CategoryId == id);
        }

        //delete category
        public bool DelCategory(int id)
        { 

            //check if has used
            if (Books.Any(b => b.BookCategoryId == id))
            {
                return false;
            }
            else
            {
                Category delCategory = this.Categories.Single(c => c.CategoryId == id);
                this.Categories.DeleteOnSubmit(delCategory);
                this.SubmitChanges();
                return true;
            }
        }
    }
}