Ответ 1
Не в том же типе. Вам нужно будет определить другой тип для каждого из разных параметров.
UPDATE
Повторное использование определений типов в вашей схеме:
<?xml version="1.0" encoding="utf-8"?>
<xs:schema elementFormDefault="qualified"
xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns="http://My.Schema.Namespace"
targetNamespace="http://My.Schema.Namespace">
<xs:element name="root">
<xs:complexType>
<xs:choice>
<xs:element name="test1" type="test1Type" />
<xs:element name="test2" type="test2Type" />
</xs:choice>
</xs:complexType>
</xs:element>
<!-- define the two root types -->
<xs:complexType name="test1Type">
<xs:all>
<xs:element name="some-element-1" type="some-element-1Type" />
<xs:element name="some-element-2" type="some-element-2Type" />
<xs:element name="some-element-3" type="some-element-3Type" />
<xs:element name="one-element" type="one-elementType" />
</xs:all>
<xs:attribute name="attrib" type="xs:string" fixed="one" />
</xs:complexType>
<xs:complexType name="test2Type">
<xs:all>
<xs:element name="some-element-1" type="some-element-1Type" />
<xs:element name="some-element-2" type="some-element-2Type" />
<xs:element name="some-element-3" type="some-element-3Type" />
<xs:element name="two-element" type="two-elementType" />
</xs:all>
<xs:attribute name="attrib" type="xs:string" fixed="two" />
</xs:complexType>
<!-- Define re-usable types-->
<xs:complexType mixed="true" name="some-element-1Type"/>
<xs:complexType mixed="true" name="some-element-2Type"/>
<xs:complexType mixed="true" name="some-element-3Type"/>
<xs:complexType mixed="true" name="one-elementType"/>
<xs:complexType mixed="true" name="two-elementType"/>
</xs:schema>
Это подтвердит:
<?xml version="1.0" encoding="utf-8" ?>
<root xmlns="http://My.Schema.Namespace">
<test1 attrib="one">
<some-element-1>sadas</some-element-1>
<some-element-2>sadas</some-element-2>
<some-element-3>sadas</some-element-3>
<one-element>sadas</one-element>
</test1>
</root>
и
<?xml version="1.0" encoding="utf-8" ?>
<root xmlns="http://My.Schema.Namespace">
<test2 attrib="two">
<some-element-1>sadas</some-element-1>
<some-element-2>sadas</some-element-2>
<some-element-3>sadas</some-element-3>
<two-element>sadas</two-element>
</test2>
</root>