RE: Empty sequences in "for" clause bindings
Stéphane Mbaye <[email protected]> Thu, 8 Jul 2004 19:52:33 +0200
| Newsgroups | gmane.comp.web.query-languages |
|---|---|
| Message-ID | <[email protected]> |
Thank you for all your answers. Regards -----Message d'origine----- De : [email protected] [mailto:[email protected]]De la part de Jerome Simeon Envoyé : jeudi 8 juillet 2004 19:43 À : Stéphane Mbaye Cc : XQuery Objet : Re: Empty sequences in "for" clause bindings Stephane, The result of your query is the empty sequence. Variables in for expressions always bind to each items in the input sequence. Since the input sequence here is empty, the $a variable is never bound to anything (it is *not* bound to the empty sequence) and the outermost for expression never executes the left-hand side sub-expression. Best, - Jerome Stéphane Mbaye <[email protected]> Sent by: [email protected] 07/08/2004 12:58 PM To "XQuery" <[email protected]> cc Subject Empty sequences in "for" clause bindings Dear all, how "for" clause tuples are generated when some of the bounded variables match the empty sequence ? For example should the following query return (1, 2, 3), an error or anything else ? for $a in (), $b in (1, 2, 3) return ($a, $b) Regards Stéphane Mbaye GAEL Consultant Cité Descartes 18, rue Albert Einstein 77420 Champs-sur-Marne France Software Director mailto:[email protected] http://www.gael.fr tel +33-(0)1 64 73 99 55 fax +33-(0)1 64 73 51 60