Click here to Skip to main content
14,093,548 members
Rate this:
Please Sign up or sign in to vote.
See more:
I'm newer to c#.I'm creating datatable(sql) which has 6 columns.Here is my table definition

spiceID varchar not allow null (primary key)
spiceName text not allow null
mfddate Datetime not allow null
expdate Datetime not allow null
storeNo varchar not allow null
storeamount float not allow null
priceper1kg float not allow null

here I not allow nulls.But If i not insert value to above columns it won't show any error msg & accept what i entre.
plz help me to solve this quickly

Here is my code.I'm creating store keeping data project

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace Ruhunu_spices_PVT_LTD
public partial class Product : Form
SqlConnection conn1 = new SqlConnection("Data Source=.\\SQLEXPRESS;AttachDbFilename=C:\\Documents and Settings\\Sachintha\\Desktop\\Ruhunu spices(PVT)LTD\\Ruhunu spices(PVT)LTD\\Rspices.mdf;Integrated Security=True;User Instance=True");
public Product()

private void Product_Load(object sender, EventArgs e)


private void button6_Click(object sender, EventArgs e)

login_view f2 = new login_view();


private void button1_Click(object sender, EventArgs e)
SqlCommand comm1 = new SqlCommand("INSERT INTO productT(spiceID,spiceName,MFDdate,EXPdate,storeNo,storeAmount,price1kg)Values(@textBox1,@comboBox1,'" + dateTimePicker1.Value.Date + "','" + dateTimePicker2.Value.Date + "',@textBox2,@textBox3,@textBox4)", conn1);

comm1.Parameters.Add("@textBox1", textBox1.Text);
comm1.Parameters.Add("@comboBox1", comboBox1.Text);
comm1.Parameters.Add("@textBox2", textBox2.Text);
comm1.Parameters.Add("@textBox3", textBox3.Text);
comm1.Parameters.Add("@textBox4", textBox4.Text);

MessageBox.Show("one row inserted");

comboBox1.Text = "";
dateTimePicker1.Value = DateTime.Today;
dateTimePicker2.Value = DateTime.Today;



private void button5_Click(object sender, EventArgs e)
String commandstring;
commandstring =string.Format( "SELECT * FROM productT WHERE spiceID='{0}'", textBox1.Text.Trim());
SqlDataReader dr1 = null;
SqlCommand com2 = new SqlCommand(commandstring, conn1);
MessageBox.Show("error in seaching", "message", MessageBoxButtons.OKCancel, MessageBoxIcon.Error);
dr1 = com2.ExecuteReader();

if (dr1.Read())
comboBox1.Text = dr1[1].ToString();
dateTimePicker1.Value = (DateTime)dr1[2];
dateTimePicker2.Value = (DateTime)dr1[3];
textBox2.Text = dr1[4].ToString();
textBox3.Text = dr1[5].ToString();
textBox4.Text = dr1[6].ToString();

MessageBox.Show("Record can not found");

Updated 2-Sep-13 17:20pm
ArunRajendra 2-Sep-13 0:02am
How are you inserting the data?
sachinthasri 4-Sep-13 12:14pm
through a windows form.This is the cord view of that windows form
Rate this: bad
Please Sign up or sign in to vote.

Solution 2

I guess its inserting empty string. If you want to insert null you need to check if the controls is empty then explicitly pass DBNull.
Rate this: bad
Please Sign up or sign in to vote.

Solution 1

Well, since you didn't provide the code you're using to set this null value and write it to the database...

A null is C# is not the same a database null, or DbNull. Without seeing your code, it's impossible to tell you how to fix it without blindly guessing.
sp_suresh 2-Sep-13 0:13am
Can't get ur question properly ur header and contain text are different
Please tell us clearly and if possible with code
Dave Kreskowiak 2-Sep-13 0:34am
Be careful who you reply to because you just replied to the wrong person.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

  Print Answers RSS
Top Experts
Last 24hrsThis month

Advertise | Privacy | Cookies | Terms of Service
Web02 | 2.8.190518.1 | Last Updated 4 Sep 2013
Copyright © CodeProject, 1999-2019
All Rights Reserved.
Layout: fixed | fluid

CodeProject, 503-250 Ferrand Drive Toronto Ontario, M3C 3G8 Canada +1 416-849-8900 x 100