尝试将付款插入数据库时出错

Question

当我试图将工资总额(input Gaji(输入数据库时，它会出现错误，并且每当我按下"Hitung total Gaji"(这是为了计算工资总额(时，欢迎标签就会不断增加一个。

我收到的错误

代码(Google Drive上的文件(：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Configuration;
public partial class Users : System.Web.UI.Page
{
int Gaji1;
String ValueGaji1;
int Waktu1;
String ValueWaktu1;
int TGK;
protected void Page_Load(object sender, EventArgs e)
{
if (Session["New"] != null)
{
WelcomeLabel.Text += Session["New"].ToString();
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["UserDataConnectionString"].ConnectionString);
conn.Open();
string checkuser = "select [Nama],[GPJ],[NIK],[Jabatan],[Gaji] from UserData where Username='" + Session["New"].ToString() + "'";
SqlCommand com = new SqlCommand(checkuser, conn);
SqlDataReader reader = com.ExecuteReader();
while (reader.Read())
{
NamaLabel.Text = reader["Nama"].ToString();
JabatanLabel.Text = reader["Jabatan"].ToString();
NIKLabel.Text = reader["NIK"].ToString();
GPJLabel.Text += reader["GPJ"].ToString();
}
conn.Close();
}
else Response.Redirect("Login.aspx");
}
protected void Button1_Click(object sender, EventArgs e)
{
Session["New"] = null;
Response.Redirect("Login.aspx");
}
protected void Button2_Click(object sender, EventArgs e)
{
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["UserDataConnectionString"].ConnectionString);
conn.Open();
string checkuser = "select [Nama],[GPJ],[NIK],[Jabatan],[Gaji] from UserData where Username='" + Session["New"].ToString() + "'";
SqlCommand com = new SqlCommand(checkuser, conn);
SqlDataReader reader = com.ExecuteReader();
while (reader.Read())
{
NamaLabel.Text = reader["Nama"].ToString();
JabatanLabel.Text = reader["Jabatan"].ToString();
NIKLabel.Text = reader["NIK"].ToString();
GPJLabel.Text = reader["GPJ"].ToString();
ValueGaji1 = reader["GPJ"].ToString();
Gaji1 = int.Parse(ValueGaji1);
ValueWaktu1 = WKTB.Text.ToString();
Waktu1 = int.Parse(ValueWaktu1);
TGK = Waktu1 * Gaji1;
TGLabel.Text = TGK.ToString() ;
}
{
conn.Close();
}
}
protected void Button3_Click(object sender, EventArgs e)
{
try
{
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["UserDataConnectionString"].ConnectionString);
conn.Open();
string InsertQuery = "insert into UserData (Gaji,WK) values (@Gaji1,@Waktu1)";
SqlCommand com = new SqlCommand(InsertQuery, conn);
com.Parameters.AddWithValue("@Gaji1", TGLabel.Text);
com.Parameters.AddWithValue("@Waktu1", WKTB.Text);
com.ExecuteNonQuery();
conn.Close();
}
catch(Exception ex)
{
Response.Write("Error: "+ex.ToString());
}
}
}

Answer 1

错误是没有为表中定义为NOT NULL的列NIK提供值。