asp.net MVC3 C＃：将查询作为参数传递并显示结果

Question

I am new to asp.net , C# and building an MVC application based on the popular Music Store application. I have my basic navigation ready and I have reached a point where I am drawing a complete blank. Basically, my asp page displays a SQL query (which is saved in SQL DB on same machine)

Need: I need to have a button next to this query which when clicked, connects to another DB through OLEDB, and runs the query and shows result in a pop up window.

Questions: How do I pass the query (which is being fetched from DB) as a parameter to code below and How do I make the results pop up in a window.

Can you please point me in correct direction. The code below is from a stand alson asp page which i used for testing connections etc. basically i need to pass the query as a parameter (replacing query seen below) and have the result in a pop window.

<%@ Import Namespace="System.Data.OleDb" %>
<%@ Import Namespace="System.Data.Odbc" %>

<script runat="server">
sub Page_Load
        Dim dbconn, sql, dbcomm, dbread
        dbconn = New OleDbConnection("Provider=xxxx;Password=xxxx;User ID=xxxx;Data Source=xxxx;Initial Catalog=xxxx;Port=xxxx;")
dbconn.Open()
        sql = "Select ID from TABLE1"
        dbcomm = New OleDbCommand(sql, dbconn)
        dbread = dbcomm.ExecuteReader() <%-- Call this method within oledbcommand--%>

  If dbread.Read = False Then
                    MsgBox("No Data Check")
                Else                    
                  Response.Write("<table>")
                    Do While dbread.Read()
                        Response.Write("<tr>")
                        Response.Write("<td>")
                        Response.Write(dbread(0))
                        Response.Write("</td>")
                        Response.Write("</tr>")
                    Loop
                  Response.Write("</table>")

 End If
         dbconn.Close()

end sub
</script>

ADDITIONAL DETAILS

CONTROLLER CLASS . .

public ActionResult DisplayResult(String Qry)        
   {
       List<QuerySet> QueryToExecute = new List<QuerySet>();
       return View(QueryToExecute);    

VIEW that provides this contoller with DATA, this is query that is fetched from my SQL DB and should be executed to a separate DB on a separate server.

<ul> 
@foreach (var ShowQueries in Model.Queriess)
{ 
    <li> 
       @Html.ActionLink(ShowQueries.Query, "DisplayResult", new { Qry = ShowQueries.Query }) 
    </li> 
} 

ISSUE: How should I use a view named 'DisplayResult' which handles the query fetched by view above and executes it agaisnt another DB. I was hoping I can use a Webform view rather than a razor view but either way i am not able to pass the parameter Any ideas are appreciated

Answer 1

The point of MVC is to move data connections out of the View (aspx page) and into a Controller.

Read some more MVC tutorials, and buy a book or two. You should actually populate the data into a viewmodel on the controller, and then pass that viewmodel to the view. This way, the view knows nothing about how to get the data -- it already got it from the controller.

Views should have the responsibility of displaying data to users over the web, not getting the data or manipulating it directly.

With that aside, here is how you would do it:

Pass the query as a string to an Action Method on a Controller (using HTTP POST or GET) using AJAX (ie jQuery $.ajax() method).

Have the action method return the HTML for your popup window, using a Partial View. You could also return Json, but I think HTML / partial view would be easier in this case. This is the method that will do your OLE DB connection, and execute the query.

In your $.ajax() success function callback, write javascript that will popup a new dialog with the partial view HTML that was returned by the controller action method.

Answer 2

You could create a class to hold the data you want to display:

namespace sample {
    class viewList
    {
        public string field1 {get;set;}
        ...
    }
}

and create a list to hold your results in your controller:

List<viewList> theList = new List<viewList>();

//Populate dbread here...

while (dbread.Read())
{    
    viewList listData = new viewList();
    listData.field1 = (dataType)dbread[0]; //Convert to your data type
    theList.Add(listData);
}

and pass this to the view:

return view(theList);

Then in your model (of model type viewList ) display your results in a table:

@model sample.viewList

<table>
    @foreach (var item in Model)
    {
        <tr>
            <td>@item.field1</td>
        </tr>
    }
</table>

ALTERNATIVE

To display in popup, put the list into the ViewBag like this:

List<viewList> theList = new List<viewList>();

//Populate dbread here...

while (dbread.Read())
{    
    viewList listData = new viewList();
    listData.field1 = (dataType)dbread[0];
    theList.Add(listData);
}

ViewBag.Items = theList;

Then in your view:

<script type="text/javascript">
    $(function() {
        var array = @Html.Raw(Json.Encode(ViewBag.Items));
        //Construct your table using the array here...
            alert(theConstructedTable);
    });
</script>