Click here to Skip to main content
12,550,111 members (45,555 online)
Rate this:
Please Sign up or sign in to vote.
See more: C# ASP.NET SQL
I have a ListView and was trying to edit the comments made by users and after which, it will be updated in my database. However, i encounter this error when i select the update button in my listView. Where have i gone wrong?

Error Message:
Cannot insert the value NULL into column 'Title', table. 
Column does not allow nulls. UPDATE fails.
The statement has been terminated.

Source Error:
An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

My .cs code:
MembershipUser currentUser = Membership.GetUser();
        Guid currentUserId = (Guid)currentUser.ProviderUserKey;
        int i = e.ItemIndex;
        TextBox tb = ListView1.Items[i].FindControl("commentContentTextBox") as TextBox;
        string test = tb.Text;
        int CommentID = Convert.ToInt16(ListView1.DataKeys[i].Value);
        string connectionString = ConfigurationManager.ConnectionStrings["ASPNETDBConnectionString"].ConnectionString;
        SqlConnection myConnect = new SqlConnection(connectionString);
        string updateSQL = "UPDATE GenBook set Title=@Title, comment=@comment, package=@package, UserId=@UserId WHERE GenBookID = @GenBookID ";
        using (SqlConnection myConnection = new SqlConnection(connectionString))
            SqlCommand myCommand = new SqlCommand(updateSQL, myConnection);
            myCommand.Parameters.AddWithValue("@GenBookID", GenBookID);
            myCommand.Parameters.AddWithValue("@Title", TextBox1.Text.Trim());
            myCommand.Parameters.AddWithValue("@comment", TextBox2.Text.Trim());
            myCommand.Parameters.AddWithValue("@UserId", currentUserId);
            myCommand.Parameters.AddWithValue("@package", package.Text.Trim());
            ListView1.EditIndex = -1;
Posted 1-Aug-12 3:35am
Kenneth Haugland 1-Aug-12 9:38am
Do you have allow null's in the SQL server?
kellycx 1-Aug-12 9:59am
No, only my package is allowed to be null. The rest i disallow them to be null.
Wes Aday 1-Aug-12 9:39am
Does Textbox1 actually contain a value?
kellycx 1-Aug-12 10:00am
For editing of comments, I only restrict the user to edit their own content of the comments. As for the title, they are not allowed to make changes.
Wes Aday 1-Aug-12 10:04am
I do not think you understand. When you debugged your code, stepping through your code using a debugger, when you are getting the error, does Textbox1 have a value? Seems to me that that is where you should be looking since that is where the error is coming from.
kellycx 1-Aug-12 10:12am
Sorry to misunderstand. I get what you mean now. I have debugged my codes and TextBox1 in fact does have a value. They are able to capture the value in TextBox1.
Rate this: bad
Please Sign up or sign in to vote.

Solution 1

Your textbOx1 dont have any text inside it. Its blank.

Make sure it is a required field. Else in table, set the column property to allow null.
kellycx 1-Aug-12 10:03am
But the TextBox1 itself already have a value. As i validated at the top before they post their comment, the Title and Content of the comments have to have some text. Therefore, even if they are not allowed to edit the title after they have posted their comment, the TextBox1 will still contain the original Text that they have entered beforehand. Isn't it?
Rate this: bad
Please Sign up or sign in to vote.

Solution 2

Cannot insert the value NULL into column 'Title', table.
Column does not allow nulls. UPDATE fails.
It's self explanatory. You are trying to insert a NULL in a column that is set not to allow null values.

Either put a default value or set column to allow NULL value.
Rate this: bad
Please Sign up or sign in to vote.

Solution 3

I think you have gotten all the information you need. You should step through the debugger, see for instance this article: 10+ powerful debugging tricks with Visual Studio[^] or this one[^]

Either as everybody has said:
TextBox1 is empty, as you probarbly would find out using the debugger.
And you have either goit to change your code to include a check for this, or
Allow nulls in the SQL database
kellycx 1-Aug-12 10:42am
I have a new error which states

Cannot insert the value NULL into column 'UserId', table

My UserId's data type is uniqueidentifier. It is encrypted and therefore, i do not really know how not to make it not null.
Kenneth Haugland 1-Aug-12 10:50am
If you replace this line:
myCommand.Parameters.AddWithValue("@Title", TextBox1.Text.Trim());
with this:
myCommand.Parameters.AddWithValue("@Title", "MyHeader");
Does it work then?
kellycx 1-Aug-12 11:10am
I managed to write off my previous error but now comes a new error that says:
Cannot insert the value NULL into column 'UserId', table
Matt T Heffron 1-Aug-12 16:59pm
Have you verified that
Guid currentUserId = (Guid)currentUser.ProviderUserKey;
has actually set a non-null value into currentUserId?
kellycx 3-Aug-12 8:29am
How am I suppose to do that?
Matt T Heffron 3-Aug-12 13:18pm
Basic Debugging!
Set a breakpoint there and look at the value.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

  Print Answers RSS
Top Experts
Last 24hrsThis month

Advertise | Privacy | Mobile
Web02 | 2.8.161021.1 | Last Updated 1 Aug 2012
Copyright © CodeProject, 1999-2016
All Rights Reserved. Terms of Service
Layout: fixed | fluid

CodeProject, 503-250 Ferrand Drive Toronto Ontario, M3C 3G8 Canada +1 416-849-8900 x 100