in asp.net, how do i update data in database with the use of textbox

Question

i have tried using this code, but it doesn't work,

it displays this error Error Updating DataObject reference not set to an instance of an object.

when i try updating, please see what i have done wrong here thanks

Protected Sub btnUpdate_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnUpdate.Click
    Dim connString As String
    connString = "Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\user\Documents\Visual Studio 2010\WebSites\boomwebsite\App_Data\playaazaleaDatabase.mdf;Integrated Security=True;User Instance=True"
    Dim cmd As SqlCommand

    Dim myConnection As New Data.SqlClient.SqlConnection(connString)
    Try
        myConnection.Open()

        cmd.CommandText = "(UPDATE members SET fname=@FNAME, lname=@LNAME, uname=@UNAME, pword=@PWORD WHERE id=@MemberID)"
        cmd.Connection = myConnection
        cmd.Parameters.AddWithValue("@MemberID", txtboxID.Text)
        cmd.Parameters.AddWithValue("@FNAME", txtboxFname.Text)
        cmd.Parameters.AddWithValue("@LNAME", txtboxLname.Text)
        cmd.Parameters.AddWithValue("@UNAME", txtboxUname.Text)
        cmd.Parameters.AddWithValue("@PWORD", txtboxPword.Text)


        cmd.ExecuteNonQuery()
        Response.Redirect("adminuser.aspx")


    Catch ex As Exception
        lblMessage.Text = "Error Updating Data" & ex.Message
    Finally
        myConnection.Close()

    End Try

And what is the error? Error messages usually try to tell you what's wrong. — David, Mar 15 '15 at 17:47
Error Updating DataObject reference not set to an instance of an object. — Boom Martinez, Mar 15 '15 at 17:48
possible duplicate of [What is a NullReferenceException and how do I fix it?](http://stackoverflow.com/questions/4660142/what-is-a-nullreferenceexception-and-how-do-i-fix-it) — David, Mar 15 '15 at 17:48
Did you check first if all your text boxes the right inputs? — abramlimpin, Mar 15 '15 at 17:50
@BoomMartinez: The linked question and answers explain it much more thoroughly. But you never initialize this variable: `Dim cmd As SqlCommand`. Since it's never initialized, it throws a `NullReferenceException` when you try to use it. — David, Mar 15 '15 at 17:52

score 0 · Answer 1 · answered Mar 15 '15 at 18:08

0

Replace Dim cmd As SqlCommand with

Dim cmd As New SqlCommand()

answered Mar 15 '15 at 18:08

VeteranLK

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in asp.net, how do i update data in database with the use of textbox

1 Answers1