XSD Parent Child Relationships - xsd

Question

I have an XSD that I created. A Transaction Header can one or more Transaction-Items. This XSD will only allow ONE Transaction Header and multiple Transaction-Items in an XML file. I am looking for MULTIPLE Transaction Headers with it's related multiple Transaction-Items. What is missing in the XSD to allow me to do this? Thanks.
<?xml version="1.0" encoding="UTF-8"?>
<!--W3C Schema generated by XMLSpy v2010 (http://www.altova.com)-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="transaction-item">
<xs:complexType>
<xs:sequence>
<xs:element ref="StartDate"/>
<xs:element ref="EndDate"/>
<xs:element ref="Amount"/>
<xs:element ref="BusinessPartnerID"/>
<xs:element ref="Description"/>
</xs:sequence>
<xs:attribute name="type" use="required">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="Production or Import"/>
<xs:enumeration value="Transfer: Release Obligation"/>
<xs:enumeration value="Transfer: Retain Obligation"/>
<xs:enumeration value="Acquire: Without Obligation"/>
<xs:enumeration value="Acquire: With Obligation"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
</xs:complexType>
</xs:element>
<xs:element name="Amount">
<xs:simpleType>
<xs:restriction base="xs:positiveInteger"/>
</xs:simpleType>
</xs:element>
<xs:element name="Year">
<xs:simpleType>
<xs:restriction base="xs:short"/>
</xs:simpleType>
</xs:element>
<xs:element name="TransactionHeader">
<xs:complexType>
<xs:sequence>
<xs:element ref="Quarter"/>
<xs:element ref="Year"/>
<xs:element ref="FuelPathwayCode"/>
<xs:element ref="PhysicalPathwayCode"/>
</xs:sequence>
</xs:complexType>
</xs:element>
<xs:element name="StartDate">
<xs:simpleType>
<xs:restriction base="xs:date"/>
</xs:simpleType>
</xs:element>
<xs:element name="Quarter">
<xs:simpleType>
<xs:restriction base="xs:byte"/>
</xs:simpleType>
</xs:element>
<xs:element name="PhysicalPathwayCode">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="PP001"/>
<xs:enumeration value="PP002"/>
<xs:enumeration value="PP003"/>
<xs:enumeration value="PP004"/>
<xs:enumeration value="PP005"/>
<xs:enumeration value="PP006"/>
<xs:enumeration value="PP007"/>
</xs:restriction>
</xs:simpleType>
</xs:element>
<xs:element name="LCFS-report">
<xs:complexType>
<xs:sequence>
<xs:element ref="TransactionHeader"/>
<xs:element ref="transaction-item" maxOccurs="unbounded"/>
</xs:sequence>
<xs:attribute name="total-sum" use="required">
<xs:simpleType>
<xs:restriction base="xs:byte"/>
</xs:simpleType>
</xs:attribute>
<xs:attribute name="detailed" type="xs:boolean" use="required"/>
<xs:attribute name="currency" use="required">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="USD"/>
</xs:restriction>
</xs:simpleType>
</xs:attribute>
</xs:complexType>
</xs:element>
<xs:element name="FuelPathwayCode">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:enumeration value="CARBOB001"/>
<xs:enumeration value="CARBOB002-HIGH"/>
<xs:enumeration value="CARBOB002-INC"/>
<xs:enumeration value="Ethanol001"/>
<xs:enumeration value="Ethanol002"/>
<xs:enumeration value="Ethanol003"/>
<xs:enumeration value="Ethanol004"/>
<xs:enumeration value="Ethanol005"/>
<xs:enumeration value="Ethanol006"/>
<xs:enumeration value="Ethanol007"/>
<xs:enumeration value="Ethanol008"/>
<xs:enumeration value="Ethanol009"/>
<xs:enumeration value="Ethanol0010"/>
<xs:enumeration value="Ethanol0012"/>
<xs:enumeration value="Fossil CNG001"/>
<xs:enumeration value="Fossil CNG002"/>
<xs:enumeration value="Biogas CNG001"/>
<xs:enumeration value="Electricity001_30"/>
<xs:enumeration value="Electricity002_27"/>
<xs:enumeration value="ULSD-CA Diesel Fuel"/>
<xs:enumeration value="Compressed Hydrogen001"/>
<xs:enumeration value="Liquid Hydrogen001"/>
<xs:enumeration value="Compressed Hydrogen002"/>
<xs:enumeration value="Compressed Hydrogen003"/>
</xs:restriction>
</xs:simpleType>
</xs:element>
<xs:element name="EndDate">
<xs:simpleType>
<xs:restriction base="xs:date"/>
</xs:simpleType>
</xs:element>
<xs:element name="Description">
<xs:simpleType>
<xs:restriction base="xs:string"/>
</xs:simpleType>
</xs:element>
<xs:element name="BusinessPartnerID">
<xs:simpleType>
<xs:restriction base="xs:short"/>
</xs:simpleType>
</xs:element>
</xs:schema>

Answer 1

First, I would convert your TransactionHeader to a separate type:
<xs:complexType name="TransactionHeaderType">
<xs:sequence>
<xs:element ref="Quarter"/>
<xs:element ref="Year"/>
<xs:element ref="FuelPathwayCode"/>
<xs:element ref="PhysicalPathwayCode"/>
</xs:sequence>
</xs:complexType>
Then you can define a new element of complex type that can contain any number of transaction headers:
<xs:element name="Root">
<xs:complexType>
<xs:sequence>
<xs:element name="TransactionHeader"
type="TransactionHeaderType"
minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
</xs:element>
By default, in XML Schema, minOccurs and maxOccurs both are set to 1 - but in a sequence, you can change that number to anything you like - including the "unbounded" for maxOccurs.
Marc