title: KDB concatenating strings inside select/exec statements
body: <p>I have a table T with column <code>Sym:`IBM`MSFT`GOOG...</code>  Want the easiest way to create new column of the form newColumn: "IBM_Buy","MSFT_Buy","GOOG_Buy",...</p>
  
  <p>The following does NOT seem to do the trick:
  <code>select ((string Sym),"_Buy") from T</code></p>