我正在设计一个使用 access 数据库作为后端的工资单系统。
目前，我在实现“打卡”功能时遇到了问题。
“打卡”按钮在数据库中插入时间。但是，当单击“打卡”按钮时，它会将数据插入新行。考虑到员工姓名，有什么办法可以避免这种情况并更新现有的最后一行。我试图用不同的方法来解决这个问题，到目前为止我还没有解决它。
有没有办法纠正这个问题？
我想我必须在某处实现一个循环来检查 emp 名称、打卡并在打卡字段中定位空值。不过不确定。
请指教。
我的代码如下；
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();
}
}