title: Update rows in SQL that retain the old value
body: <p>My table in SQL</p>
  
  <pre><code>CREATE TABLE Person(
    Person_id INT PRIMARYKEY
    Person_name NVARCHAR(250)
  )
  </code></pre>
  
  <p>Data in table:</p>
  
  <pre><code>INSERT INTO Person VALUES(1,'Peter')
  </code></pre>
  
  <p>I want update row in SQL that retain the old value.</p>
  
  <pre><code>UPDATE Person SET Person_name = 'Mary' WHERE Person_id = 1
  </code></pre>
  
  <p>This command does not work. I want after update column Person_name is value 'Peter Mary'</p>