title: hibernate update single column using criteria
body: <p>I have a table that contains mamy columns and I want to update the one or few columns of the row without effecting remaining columns
  I can write query:</p>
  
  <pre><code>update table as t set t.a=:a set t.b=:b where t.id=1
  </code></pre>
  
  <p>But seen I dont know which columns will be selected to update, and I think it is not a good idea to write every query for every scenarios. Well, I have to write query for every scenarios, but I am looking for a better way to update the table dynamically. I am thinking criteria would be a good choice. But the problem is that I have no idea how to write criteria update specific column. My code now can update the column but it would set other column to null or empty.</p>
  
  <p>What would be the good way to update specific columns without changing other columns? </p>