Invalid particle derivation by restriction for schema - xsd

Question

How can I remove the below warning in the xsd. mymain.xsd refers to mysecond.xsd
my main.xsd
<?xml version="1.0" encoding="UTF-8"?><xsd:schema elementFormDefault="qualified" targetNamespace="http://abc.com" version="2.0" xmlns:tyu="http://abc.com" xmlns:my="def.com" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<xsd:import namespace="def.com" schemaLocation="mysecond.xsd"/>
<xsd:complexType name="myType">
<xsd:complexContent>
<xsd:restriction base="my:myType">
<xsd:sequence>
<xsd:element minOccurs="0" name="rty" type="tyu:myagainType"/>
</xsd:sequence>
</xsd:restriction>
</xsd:complexContent>
</xsd:complexType>
<xsd:complexType name="myagainType">
<xsd:complexContent>
<xsd:restriction base="my:myagainType">
<xsd:sequence>
<xsd:element minOccurs="1" name="uid">
<xsd:simpleType>
<xsd:restriction base="xsd:string">
<xsd:maxLength value="1"/>
</xsd:restriction>
</xsd:simpleType>
</xsd:element>
</xsd:sequence>
</xsd:restriction>
</xsd:complexContent>
</xsd:complexType>
</xsd:schema>
mysecond.xsd
<?xml version="1.0" encoding="UTF-8"?><xsd:schema elementFormDefault="qualified" targetNamespace="def.com" version="2.0" xmlns:my="def.com" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<xsd:complexType name="myagainType">
<xsd:sequence>
<xsd:element minOccurs="0" name="klo" type="xsd:string"/>
</xsd:sequence>
</xsd:complexType>
<xsd:complexType name="myType">
<xsd:sequence>
<xsd:element minOccurs="0" name="rty" type="my:myagainType"/>
</xsd:sequence>
</xsd:complexType>
</xsd:schema>
warning
Warning 1 Invalid particle derivation by restriction - 'Derived element 'http://abc.com:rty' is not a valid restriction of base element 'def.com:rty' according to Elt:Elt -- NameAndTypeOK.'. D:\files\mymain.xsd 3 4

Answer 1

Short answer, you cannot. To begin with, your rty in mySecond.xsd is locally defined and qualified and in a different namespace than the "equivalent" rty in the main.xsd, the latter also locally defined and qualified in a different namespace.
If you go through the XML Schema spec, part 2, you'll get an explanation for each rule that applies to a valid restriction. In your case, you either use the same named element (start by "unqualifying" the rty element), or a member of a substitution group.
You obviously don't want the same element, since it'll give you the same content model - you have one element only. One reason people use restriction is to reduce the content model (remove elements from the list) and/or fiddle with min/maxOccurs for particles.
You can't do things using substitution groups since you defined rty locally; the head of a substitution group must be defined globally.
To allow for what you want, you have to completely rewrite your XSD. A better description around what exactly you're trying to achieve along with any constraints you place on XSD authoring (e.g. use of substitution groups, or redefine, or the context in which your XSDs will be used) may help others provide you with better answers.