I have a XML which reads
<Options> <option1>Y</option1> <option2>N</option2> <option3>N</option3> </Options> I would like to ensure only one child element (of Options) has value Y so that above XML is valid but not the below one.
<Options> <option1>Y</option1> <option2>Y</option2> <option3>N</option3> </Options> I tried unique and referential integrity but couldn't work out.
Any help/idea much appreciated.
You'd have to enforce such a constraint outside of XSD 1.0, but you could use xs:assert to enforce it with XSD 1.1:
<?xml version="1.0" encoding="UTF-8"?> <xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:vc="http://www.w3.org/2007/XMLSchema-versioning" vc:minVersion="1.1"> <xs:element name="Options"> <xs:complexType> <xs:sequence> <xs:element name="option1"/> <xs:element name="option2"/> <xs:element name="option3"/> </xs:sequence> <xs:assert test="count(* = 'Y') = 1"/> </xs:complexType> </xs:element> </xs:schema> Or, to avoid separately naming each option:
<?xml version="1.0" encoding="UTF-8"?> <xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:vc="http://www.w3.org/2007/XMLSchema-versioning" vc:minVersion="1.1"> <xs:element name="Options"> <xs:complexType> <xs:sequence> <xs:element name="option" maxOccurs="unbounded" /> </xs:sequence> <xs:assert test="count(option = 'Y') = 1"/> </xs:complexType> </xs:element> </xs:schema> Constraining options to be only Y or N could of course also been done if desired.
