title: Update multiple values in a single statement
body: <p>I have a master / detail table and want to update some summary values in the master table against the detail table.  I know I can update them like this:</p>
  
  <pre><code>update MasterTbl set TotalX = (select sum(X) from DetailTbl where DetailTbl.MasterID = MasterTbl.ID)
  update MasterTbl set TotalY = (select sum(Y) from DetailTbl where DetailTbl.MasterID = MasterTbl.ID)
  update MasterTbl set TotalZ = (select sum(Z) from DetailTbl where DetailTbl.MasterID = MasterTbl.ID)
  </code></pre>
  
  <p>But, I'd like to do it in a single statement, something like this:</p>
  
  <pre><code>update MasterTbl set TotalX = sum(DetailTbl.X), TotalY = sum(DetailTbl.Y), TotalZ = sum(DetailTbl.Z)
  from DetailTbl
  where DetailTbl.MasterID = MasterTbl.ID group by MasterID
  </code></pre>
  
  <p>but that doesn't work.  I've also tried versions that omit the "group by" clause.
  I'm not sure whether I'm bumping up against the limits of my particular database (Advantage), or the limits of my SQL.  Probably the latter.  Can anyone help?</p>