Student.cs

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;
using static System.Windows.Forms.VisualStyles.VisualStyleElement;

namespace Educational_Inistitute_Management
{
    public partial class Student : Form
    {
        public Student()
        {
            InitializeComponent();
        }

        private void dateTimePicker1_ValueChanged(object sender, EventArgs e)
        {
            dateTimePicker1.CustomFormat = "dd/MM/yyyy";
        }

        private void dateTimePicker1_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Back)
            {
                dateTimePicker1.CustomFormat = "";
            }
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Data Source=MY-POTATO\SQLEXPRESS;Initial Catalog=edudb;Integrated Security=True;");
            con.Open();
          
            SqlCommand cnn = new SqlCommand("insert into studentab values(@studentid,@studentname,@dateofbirth,@gender,@contactnumber,@email)",con);
            cnn.Parameters.AddWithValue("@StudentId", int.Parse(textBox1.Text));
            cnn.Parameters.AddWithValue("@StudentName",textBox2.Text);
            cnn.Parameters.AddWithValue("@DateofBirth", dateTimePicker1.Value);
            cnn.Parameters.AddWithValue("@Gender", cmbGender.SelectedItem.ToString());
            cnn.Parameters.AddWithValue("@Contactnumber", textBox5.Text);
            cnn.Parameters.AddWithValue("@Email", textBox6.Text);
            cnn.ExecuteNonQuery();
            con.Close();
            MessageBox.Show("Saved successfully !", "Save", MessageBoxButtons.OK, MessageBoxIcon.Information );


        }

        private void btnAdd_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Data Source=MY-POTATO\SQLEXPRESS;Initial Catalog=edudb;Integrated Security=True;");
            con.Open();

            SqlCommand cnn = new SqlCommand("select * from studentab", con);
            SqlDataAdapter da = new SqlDataAdapter(cnn);
            DataTable table = new DataTable();
            da.Fill(table);
            dataGridView1.DataSource = table;
        }

        private void btnUpdate_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Data Source=MY-POTATO\SQLEXPRESS;Initial Catalog=edudb;Integrated Security=True;");
            con.Open();

            SqlCommand cnn = new SqlCommand("update studentab set studentname=@studentname,dateofbirth=@dateofbirth,gender=@gender,Contactnumber=@Contactnumber,email=@email where studentid=@studentid", con);
            cnn.Parameters.AddWithValue("@StudentId", int.Parse(textBox1.Text));
            cnn.Parameters.AddWithValue("@StudentName", textBox2.Text);
            cnn.Parameters.AddWithValue("@DateofBirth", dateTimePicker1.Value);
            cnn.Parameters.AddWithValue("@Gender", cmbGender.SelectedItem.ToString());
            cnn.Parameters.AddWithValue("@Contactnumber", textBox5.Text);
            cnn.Parameters.AddWithValue("@Email", textBox6.Text);
            cnn.ExecuteNonQuery();
            con.Close();
            MessageBox.Show("updated successfully !", "Update", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

        private void btnDelete_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Data Source=MY-POTATO\SQLEXPRESS;Initial Catalog=edudb;Integrated Security=True;");
            con.Open();

            SqlCommand cnn = new SqlCommand("delete studentab where studentid=@studentid", con);
            cnn.Parameters.AddWithValue("@StudentId", int.Parse(textBox1.Text));
           
            cnn.ExecuteNonQuery();
            con.Close();
            MessageBox.Show("Deleted successfully !", "Delete", MessageBoxButtons.OK, MessageBoxIcon.Information);
        }

        private void btnNew_Click(object sender, EventArgs e)
        {
            textBox1.Text = "";
            textBox2.Text = "";
            cmbGender.SelectedIndex = -1;
            textBox5.Text = "";
            textBox6.Text = "";
        }

        private void btnDisplay_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Data Source=MY-POTATO\SQLEXPRESS;Initial Catalog=edudb;Integrated Security=True;");
            con.Open();

            SqlCommand cnn = new SqlCommand("select * from studentab", con);
            SqlDataAdapter da = new SqlDataAdapter(cnn);
            DataTable table = new DataTable();
            da.Fill(table);
            dataGridView1.DataSource = table;
        }

        private void Student_Load(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Data Source=MY-POTATO\SQLEXPRESS;Initial Catalog=edudb;Integrated Security=True;");
            con.Open();

            SqlCommand cnn = new SqlCommand("select * from studentab", con);
            SqlDataAdapter da = new SqlDataAdapter(cnn);
            DataTable table = new DataTable();
            da.Fill(table);
            dataGridView1.DataSource = table;
        }
    }
}