- From: Michael Kay <mike@saxonica.com>
- Date: Fri, 15 Jan 2010 09:29:33 -0000
- To: "'apollo'" <apollo135@gmail.com>, <xmlschema-dev@w3.org>
> > I am a new-user of xsd, and at the moment I got confusing > with some stuff Could someone please correct me if we can > declare something like: > > <xsd:sequence> > <xsd:element name="var_name" type="xsd:string"/> > > <!-- this means optional. which is similar to <xsd:element > name="var_name" type="xsd:string" use="optional"/> > --> > > <xsd:element name="var_value" type="xsd:integer" > use="required"/> </xsd:sequence> > > In some stuff, it is mentioned that 'use="optional/required" > ' can be added to attribute only. but elements are instances > of attributes . Is this correct? > There are many differences in the way attributes and elements are described in XML Schema (probably more differences than are strictly necessary). With attributes, you use use="optional|required" to indicate optionality. With elements, you use minOccurs="0|1|....". The difference of course is that elements can appear more than once, so it's possible to say things such as minOccurs="4", though this rarely arises in practice. Regards, Michael Kay http://www.saxonica.com/ http://twitter.com/michaelhkay
Received on Friday, 15 January 2010 09:30:01 UTC