Handle empty RRF files, add MTS2012AB

diff --combined sql.lisp
index dab38b8ba2d29bb059cacf073ca6fbcd23a0cf0b,32cc98d55c5c2bbdec776000392fb1962ba9d063..3847d02492692f4d5da0c2ee85f87b0be93a937e
--- 1/sql.lisp
--- 2/sql.lisp
+++ b/sql.lisp
@@@ -8,7 -8,7 +8,7 @@@
  ;;;; Created:  Apr 2000
  ;;;;
  ;;;; This file, part of UMLisp, is
- ;;;;    Copyright (c) 2000-2010 by Kevin M. Rosenberg, M.D.
+ ;;;;    Copyright (c) 2000-2012 by Kevin M. Rosenberg, M.D.
  ;;;;
  ;;;; UMLisp users are granted the rights to distribute and use this software
  ;;;; as governed by the terms of the GNU General Public License.
@@@ -16,14 -16,15 +16,14 @@@
  
  (in-package #:umlisp)
  
- (defvar +umls-sql-map+
+ (defparameter +umls-sql-map+
      '((:2004aa . "KUMLS2004AA")
        (:2006ac . "KUMLS2006AC")
        (:2006ad . "MTS2006AD")
        (:2009ab . "MTS2009AB")
 -      (:2010aa . "MTS2010AA_ALL")
 -      (:2011aa . "UMLS2011AA")
 -      (:2012aa . "MTS2012AA_ALL")))
 +      (:2010aa . "MTS2010AA")
 +      (:2012ab . "MTS2012AB")))
- (defvar +default-umls-db+ "MTS2012AB")
+ (defvar +default-umls-db+ "MTS2012AA_ALL")
  
  (defun lookup-db-name (db)
    (cdr (assoc (ensure-keyword db) +umls-sql-map+)))