Payroll System - 'clock out' functionality

Question

I am working on designing a payroll system using access database as back end.

Currently, I am facing problems implementing a 'clock out' functionality.

The 'clock in' button inserts the time in the database. However, when the 'clock out' button is clicked, it inserts the data into a new row. Is there any there any way to avoid this and to update the existing last row considering the Employee name. I have tried to approach this using different methods and so far I have not been able to solve it.

Is there any way to rectify this?

I think I would have to implement a loop somewhere to check emp name, clock in and locate null values in clock out field. Not sure though.

Please advise.

My code are as follows;

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class timecards : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        {
            if (Session["ID"] != null && Session["ID"].ToString() != "")
            {
                PanelUsersInfo.Visible = true;

            }
            else
            {
                PanelUsersInfo.Visible = false;
            }
            empLabel.Visible = false;
            mainPagebutton.Visible = false;
            logoutButton.Visible = false;
            if (Session["Title"] == null || Session["Names"] == null)
            {
                clockPanel.Visible = false;
                return;
            }
            else
            {
                mainPagebutton.Visible = true;
                logoutButton.Visible = true;
                empLabel.Visible = true;
                empLabel.Text = "<b>Hi, " + Session["Names"].ToString() + "</b>";
                nameLabel.Text = Session["Names"].ToString();
                clockinLabel.Text = DateTime.Now.ToString("HH:mm");
                Label1.Text = clockinLabel.Text;

            }
        }
    }




    protected void mainPage_Click(object sender, EventArgs e)
    {
        Response.Redirect("employeeLoggedin.aspx");
    }
    protected void logout_Click(object sender, EventArgs e)
    {
        Session.Abandon();
        Response.Redirect("default.aspx");
    }
    protected void clockinButton_Click(object sender, EventArgs e)
    {
        informLabel.Text = "Clocked in at " + Label1.Text + "";
        Label1.Visible = false;
        Label2.Visible = false;
        clockinButton.Enabled = false;
        clockoutButton.Enabled = true;

        string connectionString = "provider=Microsoft.Jet.OLEDB.4.0;" + "data source=" + Page.Server.MapPath("App_Data\\database.mdb");
        System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection(connectionString);
        System.Data.OleDb.OleDbCommand cmd = conn.CreateCommand();


        cmd.Parameters.Add("Employee", System.Data.OleDb.OleDbType.VarChar);
        cmd.Parameters["Employee"].Value = nameLabel.Text;

        cmd.Parameters.Add("Clockin", System.Data.OleDb.OleDbType.VarChar);
        cmd.Parameters["Clockin"].Value = clockinLabel.Text;

        cmd.CommandText = "INSERT INTO [timecard] ([Employee], [Clockin]) VALUES (@Employee, @Clockin)";

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




    }
    protected void clockoutButton_Click(object sender, EventArgs e)
    {
        clockoutLabel.Visible = true;
        clockoutLabel.Text = "You have now been clocked out.";
        informLabel.Visible = false;
        Label1.Visible = false;
        clockoutButton.Enabled = false;

        infoLabel.Visible = true;
        infoLabel.Text = "If you want to clock in again, please select timecard option from the main employee page.";


        string connectionString = "provider=Microsoft.Jet.OLEDB.4.0;" + "data source=" + Page.Server.MapPath("App_Data\\database.mdb");
        System.Data.OleDb.OleDbConnection conn = new System.Data.OleDb.OleDbConnection(connectionString);
        System.Data.OleDb.OleDbCommand cmd = conn.CreateCommand();

        cmd.Parameters.Add("Employee", System.Data.OleDb.OleDbType.VarChar);
        cmd.Parameters["Employee"].Value = this.nameLabel.Text;
        //String x = DateTime.Now.ToString("HH:mm");
        cmd.Parameters.Add("Clockout", System.Data.OleDb.OleDbType.VarChar);
        cmd.Parameters["Clockout"].Value = this.clockinLabel.Text;


        cmd.CommandText = "UPDATE [timecard] SET [Employee]=@Employee, [Clockout]=@Clockout";




            conn.Open();
            int numberOfRows = cmd.ExecuteNonQuery();
            conn.Close();



    }
}

Answer 1

Thank you all who helped and provided suggestions to overcome the difficulty I was encountering.

Apparently, I found a solution. It's is better to store the values as string and then use WHERE clause to update it. For some reason, it will not directly take values from the textfields.