Add Code SqlConnection con = new SqlConnection(@"Data Source=DESKTOP-ADG77QL\SQLEXPRESS;Initial Catalog=studentdb;Integrated Security=True"); con.Open(); SqlCommand cnn = new SqlCommand("insert into info_tab values(@studentid,@studentname,@age,@dob,@email,@phone)", con); cnn.Parameters.AddWithValue("@Student_Id", int.Parse(textBox1.Text)); cnn.Parameters.AddWithValue("@Student_Name", textBox2.Text); cnn.Parameters.AddWithValue("@Age", int.Parse(textBox3.Text)); cnn.Parameters.AddWithValue("@Dob", DateTime.Parse(textBox4.Text)); cnn.Parameters.AddWithValue("@Email", textBox5.Text); ...