delete row from selected gridview and database

Question

i am trying to delete a row from the gridview and database... It should be deleted if a delte linkbutton is clicked in the gridview.. I am gettin the row index as follows:

protected void LinkButton1_Click(object sender, EventArgs e)
{
  LinkButton btn = (LinkButton)sender;
  GridViewRow row = (GridViewRow)btn.NamingContainer;
  if (row != null)
  {
    LinkButton LinkButton1 = (LinkButton)sender;

    // Get reference to the row that hold the button
    GridViewRow gvr = (GridViewRow)LinkButton1.NamingContainer;

    // Get row index from the row
    int rowIndex = gvr.RowIndex;
    string str = rowIndex.ToString();
    //string str = GridView1.DataKeys[row.RowIndex].Value.ToString();
    RemoveData(str); //call the delete method

  }
}

now i want to delete it... so i am having problems with this code.. i get an error

Must declare the scalar variable "@original_MachineGroupName"... any suggestions

private void RemoveData(string item)
{
  SqlConnection conn = new SqlConnection(@"Data Source=JAGMIT-PC\SQLEXPRESS;
  Initial Catalog=SumooHAgentDB;Integrated Security=True");
  string sql = "DELETE FROM [MachineGroups] WHERE [MachineGroupID] = 
                @original_MachineGroupID;
  SqlCommand cmd = new SqlCommand(sql, conn);
  cmd.Parameters.AddWithValue("@original_MachineGroupID", item);

  conn.Open();

  cmd.ExecuteNonQuery();
  conn.Close();
}

Blockquote

<asp:SqlDataSource ID="SqlDataSource1" runat="server" 
  ConnectionString="<%$ ConnectionStrings:SumooHAgentDBConnectionString %>" 
    SelectCommand="SELECT MachineGroups.MachineGroupID, MachineGroups.MachineGroupName,
    MachineGroups.MachineGroupDesc, MachineGroups.TimeAdded, 
    MachineGroups.CanBeDeleted, COUNT(Machines.MachineName) AS Expr1, 
    DATENAME(month, (MachineGroups.TimeAdded - 599266080000000000) / 864000000000) + 
    SPACE(1) + DATENAME(d, (MachineGroups.TimeAdded - 599266080000000000) / 
     864000000000) + 
    ', ' + DATENAME(year, (MachineGroups.TimeAdded - 599266080000000000) /
    864000000000) AS Expr2 FROM MachineGroups FULL OUTER JOIN Machines ON 
    Machines.MachineGroupID = MachineGroups.MachineGroupID GROUP BY 
    MachineGroups.MachineGroupID, MachineGroups.MachineGroupName, 
    MachineGroups.MachineGroupDesc, MachineGroups.TimeAdded, 
    MachineGroups.CanBeDeleted" 
  DeleteCommand="DELETE FROM [MachineGroups] WHERE 
                  [MachineGroupID] =@original_MachineGroupID" >
        <DeleteParameters>
            <asp:Parameter Name="@original_MachineGroupID" Type="Int16" />
            <asp:Parameter Name="@original_MachineGroupName" Type="String" />
            <asp:Parameter Name="@original_MachineGroupDesc" Type="String" />
            <asp:Parameter Name="@original_CanBeDeleted" Type="Boolean" />
            <asp:Parameter Name="@original_TimeAdded" Type="Int64" />
        </DeleteParameters>   
</asp:SqlDataSource>

I still get an error : Must declare the scalar variable " @original_MachineGroupID "

Answer 1

You're not adding an @original_MachineGroupName parameter to your query. Your query references multiple variables, and you've only added one of them.

cmd.Parameters.AddWithValue("@original_MachineGroupID", item);
cmd.Parameters.AddWithValue("@original_MachineGroupName", itemName);
cmd.Parameters.AddWithValue("@original_MachineGroupDesc", itemDesc);
cmd.Parameters.AddWithValue("@original_CanBeDeleted", true);
cmd.Parameters.AddWithValue("@original_TimeAdded", time);

You'll need to find the extra information to satisfy your query, or else change your query to remove the need for them.

Answer 2

You have several parameters in you query ie @original_MachineGroupName but are only adding one actual parameter to you command object. You will need one for each parameter in the query.

Answer 3

The following code will delete the row from the database if the string you are passing to method is primary or unique key in table:

string sql = "DELETE FROM [MachineGroups] WHERE [MachineGroupID] = 
                  @original_MachineGroupID";
    SqlCommand cmd = new SqlCommand(sql, conn);
    cmd.Parameters.AddWithValue("@original_MachineGroupID", item);

Answer 4

Watch your databinding also. If you delete a row from the database, that doesn't delete the data from the gridview. You will need to re-fetch your data and databind it again.