How To Solve Object Reference Not Set To An Instance Of An Object When I Execute My Code?

Question

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C#

SQL-Server

SQL-Server-2008

, +

here my code is

C#

protected void btndelete_Click(object sender, EventArgs e)
    {
        try
        {
            cmd = new SqlCommand("Delete Employee1  Where EmployeeId=@PEmployeeId", con);
            cmd.CommandType = CommandType.Text;
            cmd.Parameters.AddWithValue("@PEmployeeId", TextBox1.Text);
            con.Open();
            cmd.ExecuteNonQuery();
            con.Close();
            lblmessage.Text = "Record deleted";
        }
        catch (NullReferenceException ex)
        {
            lblmessage.Text = ex.Message;
        }
what is this error why i'am getting this and how to solve this please help me thanks.

Posted 10-Feb-14 2:48am

raxhemanth

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Comments

Richard MacCutchan 10-Feb-14 8:56am

Use your debugger to step through the code and check the value of each variable that you are trying to use. Are you sure that your connection variable con has been initialised properly?

Karthik_Mahalingam 10-Feb-14 8:58am

remove the try catch and see in which line you are getting this error

3 solutions

Solution 1

Make sure that con object is not null.
Initialize the SqlConnection to the con object before using this event

Posted 10-Feb-14 3:03am

Karthik_Mahalingam

Solution 2

May be your database Connection is not established properly...

Posted 10-Feb-14 3:12am

Ashwani Gusain

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Siva Hyderabad · Accepted Answer · 2014-02-10T03:23:00

Normally, you would try to read a connection string from Web.Config by using its name:

C#

<connectionStrings>
  <add name="LoggingDatabase" connectionString="Database=XXX;Data Source=XXX;Initial Catalog=XXX;Integrated Security=True"/>

You appear to be trying to retrieve a connection string by using the string itself as the name...which is why you get the error, it doesn't exist so it returns null.