Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people, just like you, are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
Solved

Sorting linked tables in gridview

Posted on 2014-01-27
2
298 Views
Last Modified: 2014-01-27
Hello:

I am getting this error message
Object reference not set to an instance of an object.

on this line:
dataset.Tables["Test"].DefaultView.Sort = sortExpression;

    private void BindGrid()
    {
        SqlConnection conn;
        DataSet dataset = new DataSet();
        SqlDataAdapter adapter;
        if (ViewState["dataset"] == null)
        {
            string connectionString = "Data Source=BirdCage;Initial Catalog=BirdCageDB;User Id=User;Password=BCUser;";
            conn = new SqlConnection(connectionString);
            adapter = new SqlDataAdapter("SELECT Test.ID, Test.PersonName, Data.DeptID FROM Test INNER JOIN Data ON Test.ID = Data.AutoID", conn);
            adapter.Fill(dataset);
            ViewState["datadset"] = dataset;
        }
        else
        {
            dataset = (DataSet)ViewState["dataset"];
        }
        string sortExpression;
        if (gridSortDirection == SortDirection.Ascending)
        {
            sortExpression = gridSortExpression + " ASC";
        }
        else
        {
            sortExpression = gridSortExpression + " DESC";
        }
        dataset.Tables["Test"].DefaultView.Sort = sortExpression;
        ViewData.DataSource = dataset.Tables["Test"].DefaultView;
        ViewData.DataBind();
    }
    protected void ViewData_Sorting(object sender, GridViewSortEventArgs e)
    {
        string sortExpression = e.SortExpression;
        if (sortExpression == gridSortExpression)
        {
            if (gridSortDirection == SortDirection.Ascending)
            {
                gridSortDirection = SortDirection.Descending;
            }
            else
            {
                gridSortDirection = SortDirection.Ascending;
            }
        }
        else
        {
           gridSortDirection = SortDirection.Ascending;
        }
        gridSortExpression = sortExpression;
        BindGrid();
    }
    private SortDirection gridSortDirection
    {
        get
        {
            if (ViewState["GridSortDirection"] == null)
            {
                ViewState["GridSortDirection"] = SortDirection.Ascending;
            }
            return (SortDirection)ViewState["GridSortDirection"];
        }
        set
        {
            ViewState["GridSortDirection"] = value;
        }
    }
    private string gridSortExpression
    {
        get
        {
            if (ViewState["GridSortExpression"] == null)
            {
                ViewState["GridSortExpression"] = "ID";
            }
            return (string)ViewState["GridSortExpression"];
        }
        set
        {
            ViewState["GridSortExpression"] = value;
        }
    }

Open in new window

0
Comment
Question by:RecipeDan
2 Comments
 
LVL 40

Accepted Solution

by:
Kyle Abrahams earned 500 total points
ID: 39813671
Try
  dataset.Tables[0].DefaultView.Sort = sortExpression

to find out what the name is set a breakpoint after the fill . . . in the immediate window type
"?dataset.Tables[0].TableName" without the quotes.

You could also call:
adapter.Fill(dataset, "Test");
0
 
LVL 1

Author Comment

by:RecipeDan
ID: 39813787
This worked:

adapter.Fill(dataset, "Test");

Thanks for your help
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

ASP.Net to Oracle Connectivity Recently I had to develop an ASP.NET application connecting to an Oracle database.As I am doing it first time ,I had to solve several problems. This article will help to such developers  to develop an ASP.NET client…
Real-time is more about the business, not the technology. In day-to-day life, to make real-time decisions like buying or investing, business needs the latest information(e.g. Gold Rate/Stock Rate). Unlike traditional days, you need not wait for a fe…
With Secure Portal Encryption, the recipient is sent a link to their email address directing them to the email laundry delivery page. From there, the recipient will be required to enter a user name and password to enter the page. Once the recipient …
A short tutorial showing how to set up an email signature in Outlook on the Web (previously known as OWA). For free email signatures designs, visit https://www.mail-signatures.com/articles/signature-templates/?sts=6651 If you want to manage em…

840 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question