title: TSQL After Update Trigger check for update on multiple columns in one IF UPDATE
body: <p>The basic syntax for an After Update trigger in TSQL is:</p>
  
  <pre><code>CREATE TRIGGER [dbo].[triggerName]
     ON [dbo].[Table]
     AFTER UPDATE, INSERT --trigger when Update or Insert in table
  AS BEGIN
      SET NOCOUNT ON;
      IF UPDATE (ColumnA) -- if ColumnA updates start
      begin
          UPDATE Table
          SET ColumnC = ColumnA + ColumnB -- recalculate Column C
      end 
      IF UPDATE (ColumnB) -- if ColumnB updates start
      begin
          UPDATE Table
          SET ColumnC = ColumnA + ColumnB -- recalculate Column C
      end 
  END
  </code></pre>
  
  <p>Now above could work I guess, but is it possible to combine both IF UPDATES in one?:
  Something like this:</p>
  
  <pre><code>IF UPDATE (ColumnA) OR (ColumnB) -- if ColumnA or ColumnB updates start
          begin
              UPDATE Table
              SET ColumnC = ColumnA + ColumnB -- recalculate Column C
          end 
  </code></pre>
  
  <p>You could use a computed column of course, but out of curiosity I'd like to know if you can check for updates on multiple columns at once in a trigger and then do the after update trigger modification. </p>