CODEWITHSUNDEEP
c#sqlasp.net
Legend1989
Legend1989

Reputation: 664

There is no row at position 0 query

I am new to C# and .NET and I am struggling with some code that is throwing a error, the error it throws is:

There is no row at position 0.

Here is my code that I got, as far as I can see if the sql returs 0 rows the 404 should be displayed, however at the moment I am getting a stack error.

This is the stack error:

[IndexOutOfRangeException: There is no row at position 0.]
System.Data.RBTree`1.GetNodeByIndex(Int32 userIndex) +2409382
System.Data.DataRowCollection.get_Item(Int32 index) +20
Targetting.ArticlePage.Page_Load(Object sender, EventArgs e) in C:\SRC\Site1\Web\Article\Trunk\Article.aspx.cs:78
CommonBasePageClass.BaseWebPage.OnLoad(EventArgs e) +50
System.Web.UI.Control.LoadRecursive() +71
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +3178

Here is the code that I believe is throwing the error:

//If the article is Archived or Unknown or has expired then all users should be shown an "unavailable" message instead of the content
if (dt.Rows[0]["pagestatusid"].ToString() == "3" || dt.Rows[0]["pagestatusid"].ToString() == "0" || (dt.Rows[0]["expirydate"] != DBNull.Value && DateTime.Parse(dt.Rows[0]["expirydate"].ToString()) < DateTime.Now))
{
    pnlDraftWarning.Visible = false;
    pnlContentNotAvailable.Visible = true;
    pnlMainContent.Visible = false;

    Response.StatusCode = 404;
    return;
}

Upvotes: 2

Views: 24355

Answers (3)

Jawwad Ali Khan
Jawwad Ali Khan

Reputation: 17

you should use either

if(dt.Rows.Count > 0)

or

if(dt == null)

Upvotes: 0

Kami
Kami

Reputation: 19407

The error is that there is no data at row zero - the table dt is empty.

The code is expecting there to be atleast one row 

if (dt.Rows[0]["pagestatusid"].ToString() == "3" || dt.Rows[0]["pagestatusid"].ToString() == "0" || (dt.Rows[0]["expirydate"] != DBNull.Value && DateTime.Parse(dt.Rows[0]["expirydate"].ToString()) < DateTime.Now))
{
}

You can work around this issue by adding a guard condition to check if there is data.

if (dt == null ||
    dt.Rows.Count < 1 ||
    dt.Rows[0]["pagestatusid"].ToString() == "3" ||
    dt.Rows[0]["pagestatusid"].ToString() == "0" ||
    (dt.Rows[0]["expirydate"] != DBNull.Value &&
     DateTime.Parse(dt.Rows[0]["expirydate"].ToString()) < DateTime.Now))
{
  // other code
}

or identify the reason why there might not be data when you are expecting there to be some.

Upvotes: 4

Giannis Paraskevopoulos
Giannis Paraskevopoulos

Reputation: 18411

Check if there is any rows:

if (
       dt.Rows.Count()>0 && 
       (
           dt.Rows[0]["pagestatusid"].ToString() == "3" || 
           dt.Rows[0]["pagestatusid"].ToString() == "0" || 
           (
               dt.Rows[0]["expirydate"] != DBNull.Value && 
               DateTime.Parse(dt.Rows[0]["expirydate"].ToString()) < DateTime.Now
           )
       )
   )
{
    pnlDraftWarning.Visible = false;
    pnlContentNotAvailable.Visible = true;
    pnlMainContent.Visible = false;

    Response.StatusCode = 404;
    return;
}

Upvotes: 0

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