In XSD, how can I make the elements occur in freewill order? (Tested in SQL 2005 Expr

[mycwcgr]

In XSD, how can I make the elements occur in freewill order? (Tested in SQL 2005 Express Edition)


I know if I add the keyword "sequence" in a XSD, the "Title" element must occur before "Url" element in XML. (Section A)

now I hope "Title" and "Url" elements may occur in freewill order, that mean the following two codes are OK!

Title="aa"
Url=="bb"

or

Url=="bb"
Title="aa"



I try to write the xsd just like Section B (I think the keyword "group" will be effectually), but I get the error information below 沁SQL 2005!

.Net SqlClient Data Provider: Msg 2299, Level 16, State 1, Line 1
Missing attribute 'ref'


Why? In XSD, how can I make the elements occur in freewill order? thanks





//-----------------------------Section A ------------------------------------
CREATE XML SCHEMA COLLECTION [dbo].[w1]
AS N'

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns="http://www.hellocw.com/onlinebookmark"
targetNamespace="http://www.hellocw.com/onlinebookmark"
elementFormDefault="qualified">

<xsd:element name="Folder" type="bookmarkType"/>

<xsd:complexType name="bookmarkType">

<xsd:sequence>
<xsd:element name="Title" type="xsd:string" />
<xsd:element name="Url" type="xsd:string" />
</xsd:sequence>

</xsd:complexType>

</xsd:schema>

'
GO
//-----------------------------Section A ------------------------------------





//-----------------------------Section B ------------------------------------
CREATE XML SCHEMA COLLECTION [dbo].[w2]
AS N'

<xsd:schema xmlns:xsd="http://www.w3.org/2001/XMLSchema"
xmlns="http://www.hellocw.com/onlinebookmark"
targetNamespace="http://www.hellocw.com/onlinebookmark"
elementFormDefault="qualified">

<xsd:element name="Folder" type="bookmarkType"/>

<xsd:complexType name="bookmarkType">

<xsd:group>
<xsd:element name="Title" type="xsd:string" />
<xsd:element name="Url" type="xsd:string" />
</xsd:group>

</xsd:complexType>


</xsd:schema>

'
GO
//-----------------------------Section B ------------------------------------

[KC-Luck]

<xsd:group/> is not designed to be used as you are trying.
you declare the <xsd:group name="yourGroup">... just under documentElement.
then within a complexType you would put:
choice, all, or sequence --> then <group ref="yourGroup" minOccurs="0" maxOccurs="unbounded"/>

<xsd:all> allows free flow, but only 0 or 1 occurances;
<xsd:choice min 0 max unbounded> will give you a freeflow, but you will not be able to set any restraints on howMany, or sequence.

bit complicated, but sacrifices must be made for regidity.