+ (case (database-underlying-type database)
+ (:mysql
+ (etypecase val
+ (string (if (string= "0" val) nil t))
+ (integer (if (zerop val) nil t))))
+ (:postgresql
+ (if (eq :odbc (database-type database))
+ (if (string= "0" val) nil t)
+ (equal "t" val)))
+ (t
+ (equal "t" val))))