Use the global function rwdbExists(const RWDBSelectorBase&).  Eg,

  extern RWDBSelector mySelector;
  extern RWDBDatabase db;
  RWDBSelector s = db.selector();
  s << "Yes it does";
  s.where(rwdbExists(mySelector));

  // etc.

  This is equivalent to the SQL  "Select 'Yes it does' where
     exists( <text of mySelector here> )

  Caveat:  there may be restrictions on what you can put into the
  exists clause.  For example, my MS SQL-Server 6.0 claims this
  is a syntax error:  "select 'yes' where exists( select name, id
  from sysobjects where id < 10 )"  It's ok if there's only one
  item selected in the inner select.  

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Stan Sulsky                              

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I'm drawing a blank on how one does an existence test using SQL.
All I want to do is ascertain whether some row in a table exists.
I'm using Rogue Wave dbtools.h++
How would I code this using a RWDBReader, RWDBSelector, etc.?

Thanks

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Christopher Ruegger                 phone:   (301) 925-1164