Hello, if I am getting the validation error in xmlSpy:

'wfs:BaseRequestType' must refer to an existing simple or complex type

for the schema with below snippet (see 2 bolded most-relevent lines):

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" elementFormDefault="qualified" attributeFormDefault="unqualified"
xmlns:wfs="http://www.opengis.net/wfs"xmlns:ogc="http://www.opengis.net/ogc"
>
<xs:element name="GetFeature" type="wfs:GetFeatureType"/>
<xs:complexType name="GetFeatureType">
<xs:complexContent>
<xs:extension base="wfs:BaseRequestType"><xs:sequence>
<xs:element ref="wfs:Query" maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="resultType" type="wfs:ResultTypeType" use="optional" default="results"/>
<xs:attribute name="outputFormat" type="xs:string" use="optional" default="text/xml; subtype=3.1.1"/>
<xs:attribute name="maxFeatures" type="xs:positiveInteger" use="optional"/>
<xs:attribute name="traverseXlinkDepth" type="xs:string" use="optional"/>
<xs:attribute name="traverseXlinkExpiry" type="xs:positiveInteger" use="optional"/>
</xs:extension>
</xs:complexContent>
</xs:complexType>
.
.
.

what is the likely problem? I would think that with the "wfs=" namespace reference (near top of snippet) present, then the tool should be able to resolve the type. I am getting similar errors, in fact, for all lines with either "wfs: “ and “ogc: “. Any help is appreciated. Thank you.

Unless you have a 'targetNamespace' attribute you're not showing the then you need to include that attribute as well as the xmlns:wfs namespace declaration.

I am assuming that BaseRequestType is defined elsewhere in your schema?

If it is not then you need to import the schema definition for that namespace - don't get confused by a namespace declaration - just because it looks like a URL doesn't mean the parser automatically downloads the schema declaration from that location.

__________________
/- Sam Judson : Wrox Technical Editor -/

Think before you post: What have you tried?

<xsl:import schemaLocation="http://schemas.opengis.net/wfs/1.1.0/wfs.xsd" namespace="http://www.opengis.net/wfs"/>

__________________
/- Sam Judson : Wrox Technical Editor -/

Think before you post: What have you tried?

Are there any xs:import or xs:include elements in that schema?
Also does that schema not have a targetNamespace attribute?

__________________
Martin Honnen
Microsoft MVP (XML, Data Platform Development) 2005/04 - 2013/03
My blog

Many thanks to you guys. I simply needed:

<xs:import namespace="http://www.opengis.net/wfs" schemaLocation="http://schemas.opengis.net/wfs/1.1.0/wfs.xsd"/>
<xs:import namespace="http://www.opengis.net/ogc" schemaLocation="http://schemas.opengis.net/filter/1.1.0/filter.xsd"/>