title: how to query database and show information in winforms?
body: <p>I have a <code>Patient</code> database entity.
  i would like to query and check if a <code>Patient</code> record already exists using a given <code>id</code>.</p>
  
  <p>the result (such as <em><code>that id already exists</code></em>) should be stored in <strong><code>textBox1</code></strong> and presented to the user.</p>
  
  <p>This is what i've got so far:</p>
  
  <pre><code>using System;
  using System.Collections.Generic;
  using System.ComponentModel;
  using System.Data;
  using System.Data.SqlClient;
  using System.Drawing;
  using System.Linq;
  using System.Text;
  using System.Windows.Forms;
  using System.Security.Cryptography;
  
  namespace LMS {
      public partial class PIDD: Form {
          public PIDD() {
              InitializeComponent();
          }
  
          private void button1_Click(object sender, EventArgs e) {
              this.Close();
              frmMed Med = new frmMed();
              Med.Show();
          }
  
          private void textBox1_TextChanged(object sender, EventArgs e) {
  
          }
      }
  }
  </code></pre>
  
  <p>How should I continue from this point?</p>