使用javascript而不是C＃的ASP.net Web表单访问数据库

Question

I have an online shopping application where I have product categories. I have the following method to retrieve the categories from the database and it is written in C#.

public IQueryable<Category> GetProductCategories()
    {
        var _db = new BundleShop.Models.ProductContext();
        IQueryable<Category> query = _db.Categories;
        return query;
    }

Can anybody give me a hand writing the same code in javascript?

Answer 1

You cannot make a javascript call to the database. The solution you are probably looking for is implementing a web service that exposes this functionality and call the webservice from the javascript (via ajax call).

Answer 2

You can call with javascript one server side function that query the database.

server side (maybe in your home.aspx page)

[WebMethod()]
[ScriptMethod(UseHttpGet = false, ResponseFormat = ResponseFormat.Json)]
public string[] GetProducts()
{
        var _db = new BundleShop.Models.ProductContext();
        IQueryable<Category> query = _db.Categories;
        return query.Cast<MyEntityType>().ToArray();;
}

define your MyEntityType Type

public Class MyEntityType {
    public int Order;
    pubic string Description;
}

script side

$.ajax({
   type: "POST",
   url: "/home.aspx/GetProducts",
   success: onsuccess,
   dataType: 'json',
   error: onerror
 });

manage results in success jquery function

function onsuccess(data, status, xmlHttpRequest) {
      //manage data variable here (cycle its elements, put them in page)             
}

summarizing :

1. Create server side function to query data
2. Create script function to call server side function
3. Manage json results in success jquery ajax call