title: Update multiple rows with different values in SQL
body: <p>I have a table like this:</p>
  
  <pre><code>SKU            Size
  A              10
  B              10
  C              10
  D              10
  E              10
  F              10
  G              10
  </code></pre>
  
  <p>I want to change it to:</p>
  
  <pre><code>SKU            Size
  A              20
  B              10
  C              30
  D              10
  E              80
  F              10
  G              60
  </code></pre>
  
  <p>I have more than 3000 rows of records to update. How can I do that with SQL update command ?</p>