i am new to c#.net and i like to program,i have a table named login which have id,username and password columns, i also have a login form to send data in Login table i want to store input data in table but i am receiving the error - " An unhandled exception of type 'System.ArgumentException' occurred in System.Data.dll". what am i doing wrong? i am using visual studio 2015.please help! thank you.here is my code -
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace login
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
private void btnLogin_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Log.mdf;Integrated Security=True;Connect Timeout=30;");
SqlDataAdapter sda = new SqlDataAdapter("Select Count (*) From Login where username ='" + userNametextBox.Text + "'and password='" + PasswordtextBox.Text + "'", con);
DataTable dt = new DataTable();
sda.Fill(dt);
if (dt.Rows[0][0].ToString() == "1")
{
this.Hide();
Main ss = new Main();
ss.Show();
}
else
{
MessageBox.Show("Please check your username and password ");
}
}
private void btnInsert_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(@"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\Log.mdf;Integrated Security=True;Connect Timeout=30;");
SqlDataAdapter sda = new SqlDataAdapter("Select Count (*) From Login where username ='" + userNametextBox.Text + "'and password='" + PasswordtextBox.Text + "'", con);
SqlCommandBuilder cmb = new SqlCommandBuilder(sda);
//DataTable dt = new DataTable();
DataSet ds = new DataSet();
sda.Fill(ds, "Login");
ds.Tables[0].Constraints.Add("Id", ds.Tables[0].Columns[0], true);
DataRow row;
row = ds.Tables[0].NewRow();
row["username"] = userNametextBox.Text;
row["password"] = PasswordtextBox.Text;
ds.Tables[0].Rows.Add(row);
sda.Update(ds.Tables[0]);
MessageBox.Show("record added", this.Text);
}
private void userNametextBox_TextChanged(object sender, EventArgs e)
{
}
}
}