title: C# SqlCommand query with update
body: <p>I tried to find it. But I can't found exactly my answer. So I decide to ask this questions. I need your help.</p>
  
  <p>I want add value into table value without overwriting Debit, Score column. It will add current value.</p>
  
  <pre><code>cmd = new SqlCommand("UPDATE Users SET Debit=@debit, 
                                         Score=@score 
                                   WHERE Phone=@phone", con);
  
  con.Open();
  
  cmd.Parameters.AddWithValue("@phone", textBox1.Text);
  cmd.Parameters.AddWithValue("@debit", textBox2.Text);
  cmd.Parameters.AddWithValue("@score", textBox3.Text);
  
  cmd.ExecuteNonQuery();
  
  MessageBox.Show("Амжилттай");
  con.Close();
  </code></pre>
  
  <p>For example:</p>
  
  <pre><code>Table, Phone: 999 | Debit: 1500 | Score: 100 //current &lt;br&gt;
  </code></pre>
  
  <p>When I add value from textBox1 = 999, textBox2 = 500, textBox3 = 50 </p>
  
  <pre><code>Table, Phone: 999, Debit: 2000, Score: 150 //updating like that 
  </code></pre>
  
  <p>I know SQL query like that. But I don't know how to write code in <code>SqlCommand</code> </p>
  
  <pre><code>UPDATE Users 
  SET Debit = Debit + [user input], Score = Score + [user input] 
  WHERE = Phone
  </code></pre>
  
  <p>Any suggestions? </p>
  
  <p>(Sorry for my horrible English I hope you guys understand What I'm trying to ask) </p>
  
  <p>Thanks</p>