UA Part 4: Services - B.2 Complex Examples of Query Filters

These query examples illustrate complex filters. The following conventions apply to these examples with regard to Attribute operands (for a definition of these operands, see 7.7.4).

AttributeOperand: Refers to a Node, an Attributeof a Nodeor the Value Attributeof a Propertyassociated with a Node. In the examples character names of ExpandedNodeIdare used instead of an actual ExpandedNodeId, this also applies to AttributeIds.
The string representation of relative paths is used instead of the actual structure.
The NamespaceIndexused in all examples is 12 (it could just as easily have been 4 or 23 or any value). For more information about NamespaceIndex, see OPC 10000-3. The use of the NamespaceIndexillustrates that the information model being used in the examples is not a model defined by this document, but one created for the examples.

B.2.2 Used type model

The following examples use the type model described below. All Propertyvalues are assumed to be string unless otherwise noted

New Reference types:

"HasChild" derived from HierarchicalReference.

"HasAnimal" derived from HierarchicalReference.

"HasPet" derived from HasAnimal.

"HasFarmAnimal" derived from HasAnimal.

"HasSchedule" derived from HierarchicalReference.

PersonType derived from BaseObjectType adds:

HasProperty "LastName".

HasProperty "FirstName".

HasProperty "StreetAddress".

HasProperty "City".

HasProperty "ZipCode".

May have HasChild reference to a node of type PersonType.

May have HasAnimal reference to a node of type AnimalType (or a subtype of this Referencetype).

AnimalType derived from BaseObjectType adds:

May have HasSchedule reference to a node of type FeedingScheduleType.

HasProperty "Name".

DogType derived from AnimalType adds:

HasProperty "NickName".

HasProperty "DogBreed".

HasProperty "License".

CatType derived from AnimalType adds:

HasProperty "NickName".

HasProperty "CatBreed".

PigType derived from AnimalType adds:

HasProperty "PigBreed".

ScheduleType derived from BaseObjectType adds:

HasProperty "Period".

FeedingScheduleType derived from ScheduleType adds:

HasProperty "Food".

HasProperty "Amount" (Stored as an Int32).

AreaType derived from BaseObjectTypeis just a simple Folderand contains no Properties.

This example type system is shown in Figure B.3. In this Figure, the OPC UA notation is used for all Referencesto ObjectTypes, Variables, Propertiesand subtypes.Additionally, supported Referencesare contained in an inner box. The actual references only exist in the instances, thus, no connections to other Objectsare shown in the Figure and they are subtypes of the listed Reference.

Figure B.3– Example Type Nodes

A corresponding example set of instances is shown in Figure B.4. These instances include a type Referencefor Objects. Properties also have type References, but the Referencesare omitted for simplicity. The name of the Objectis provided in the box and a numeric instance NodeIdin brackets. Standard ReferenceTypesuse the OPC UA notation, custom ReferenceTypesare listed as a named Reference. For Properties, the BrowseName, NodeId, and Valueare shown. The Nodesthat are included in a View(View1) are enclosed in the coloured box. Two Area nodes are included for grouping of the existing person nodes. All custom nodes are defined in namespace 12 which is not included in Figure B.4.

Figure B.4– Example Instance Nodes

B.2.3 Example Notes

For all of the examples in 7.7.4, the type definition Nodeis listed in its symbolic form, in the actual call it would be the ExpandedNodeIdassigned to the Node. The Attribute is the symbolic name of the Attribute, in the actual call they would be translated to the IntegerIdof the Attribute. Also in all of the examples the BrowseNameis included in the result table for clarity; normally this would not be returned.

All of the examples include the following items:

an English description of the object of the query;
an SQL like description of the query;
a table that has a NodeTypeDescription of the items that are to be returned;
a figure illustrating the query filter;
a table describing the content filter;
a table describing the resulting dataset.

The examples assume namespace 12 is the namespace for all of the custom definitions described for the examples.

B.2.4 Example 1

This example requests a simple layered filter, a person has a pet and the pet has a schedule.

Example 1: Get PersonType.LastName, AnimalType.Name, ScheduleType.Period where the Person Has a Pet and that Pet Has a Schedule.

The NodeTypeDescriptionparameters used in the example are described in Table B.3.

Table B.3– Example 1 NodeTypeDescription

Type Definition Node	Include Subtypes	QueryDataDescription
Type Definition Node	Include Subtypes	Relative Path	Attribute	Index Range
PersonType	FALSE	“.12:LastName”	value	N/A
		“<12:HasPet>12:AnimalType. 12:Name”	value	N/A
		“<12:HasPet>12:AnimalType<12:HasSchedule> 12:Schedule. 12:Period”	value	N/A

The corresponding ContentFilteris illustrated in Figure B.5.

Figure B.5– Example 1 Filter

Table B.4describes the ContentFilterelements, operators and operands used in the example.

Table B.4– Example 1 ContentFilter

Element[]	Operator	Operand[0]	Operand[1]	Operand[2]	Operand[3]
1	RelatedTo	AttributeOperand = NodeId: PersonType, BrowsePath “.”, Attribute: NodeId	ElementOperand = 2	AttributeOperand = NodeId: HasPet, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’
2	RelatedTo	AttributeOperand = NodeId: AnimalType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: ScheduleType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: HasSchedule, BrowsePath “.”, Attribute: NodeId	LiteralOperand= ‘1’

Table B.5describes the QueryDataSetthat results from this query if it were executed against the instances described in Figure B.4

Table B.5– Example 1 QueryDataSets

NodeId	TypeDefinition NodeId	RelativePath	Value
12:30 (JFamily1)	PersonType	“.12:LastName”	Jones
		“<12:HasPet>12:AnimalType. 12:Name”	Rosemary
		“<12:HasPet>12:AnimalType. 12:Name”	Basil
		“<12:HasPet>12:AnimalType<12:HasSchedule> 12:Schedule.12:Period”	Hourly
			Daily
12:42(HFamily1)	PersonType	“.12:LastName”	Hervey
		“<12:HasPet>12:AnimalType. 12:Name”	Oliver
		“<12:HasPet>12:AnimalType<12:HasSchedule> 12:Schedule.12:Period”	Daily

NOTE The RelativePath column and browse name (in parentheses in the NodeIdcolumn) are not in the QueryDataSet and are only shown here for clarity. The TypeDefinition NodeIdwould be an integer not the symbolic name that is included in the table.

The Value column is returned as an array for each Nodedescription, where the order of the items in the array would correspond to the order of the items that were requested for the given Node Type. In Addition, if a single Attributehas multiple values then it would be returned as an array within the larger array, for example in this table Rosemary and Basil would be returned in a array for the .<HasPet>.AnimalType.Name item. They are show as separate rows for ease of viewing. The actual value array for JFamily1 would be (“Jones”, {“RoseMary”, ”Basil”}, {“Hourly”, “Daily”})

B.2.5 Example 2

The second example illustrates receiving a list of disjoint Nodesand also illustrates that an array of results can be received.

Example 2: Get PersonType.LastName, AnimalType.Name where a person has a child or (a pet is of type cat and has a feeding schedule).

The NodeTypeDescription parameters used in the example are described in Table B.6.

Table B.6– Example 2 NodeTypeDescription

Type Definition Node	Include Subtypes	QueryDataDescription
Type Definition Node	Include Subtypes	Relative Path	Attribute	Index Range
PersonType	FALSE	“.12:LastName”	Value	N/A
AnimalType	TRUE	“.12:Name”	Value	N/A

The corresponding ContentFilter is illustrated in Figure B.6.

Figure B.6– Example 2 filter logic tree

Table B.7describes the elements, operators and operands used in the example. It is worth noting that a CatType is a subtype of AnimalType.

Table B.7– Example 2 ContentFilter

Element[]	Operator	Operand[0]	Operand[1]	Operand[2]	Operand[3]
0	Or	ElementOperand=1	ElementOperand = 2
1	RelatedTo	AttributeOperand = NodeId: PersonType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: PersonType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: HasChild, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’
2	RelatedTo	AttributeOperand = NodeId: CatType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: FeedingScheduleType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: HasSchedule, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’

The results from this query would contain the QueryDataSetsshown in Table B.8.

Table B.8– Example 2 QueryDataSets

NodeId		TypeDefinition NodeId	RelativePath	Value
12:30 (Jfamily1)	PersonType		. 12:LastName	Jones
12:42 (HFamily1)	PersonType		. 12:LastName	Hervey
12:48 (HFamily2)	PersonType		. 12:LastName	Hervey
12:70 (Cat1)	CatType		. 12:Name	Rosemary
12:74 (Cat2)	CatType		. 12:Name	Basil

NOTE The relative path column and browse name (in parentheses in the NodeIdcolumn) are not in the QueryDataSetand are only shown here for clarity. The TypeDefinition NodeIdwould be a NodeIdnot the symbolic name that is included in the table.

B.2.6 Example 3

The third example provides a more complex Queryin which the results are filtered on multiple criteria.

Example 3: Get PersonType.LastName, AnimalType.Name, ScheduleType.Period where a person has a pet and the animal has a feeding schedule and the person has a Zipcode = ‘02138’ and (the Schedule.Period is Daily or Hourly) and Amount to feed is > 10.

Table B.9describes the NodeTypeDescription parameters used in the example.

Table B.9– Example 3 - NodeTypeDescription

Type Definition Node	Include Subtypes	QueryDataDescription
Type Definition Node	Include Subtypes	RelativePath	Attribute	Index Range
PersonType	FALSE	“12:LastName”	Value	N/A
		“<12:HasPet>12:AnimalType. 12:Name”	Value	N/A
		“<12:HasPet>12:AnimalType<12:HasSchedule> 12:FeedingSchedule.Period”	Value	N/A

The corresponding ContentFilteris illustrated in Figure B.7.

Figure B.7– Example 3 filter logic tree

Table B.10describes the elements, operators and operands used in the example.

Table B.10– Example 3 ContentFilter

Element[]	Operator	Operand[0]	Operand[1]	Operand[2]	Operand[3]
0	And	Element Operand= 1	ElementOperand = 2
1	And	ElementOperand = 4	ElementOperand = 6
2	And	ElementOperand = 3	ElementOperand = 9
3	Or	ElementOperand = 7	ElementOperand = 8
4	RelatedTo	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId	ElementOperand = 5	AttributeOperand = NodeId: 12:HasPet, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’
5	RelatedTo	AttributeOperand = Node: 12:AnilmalType, BrowsePath “.”, Attribute: NodeId Alias: AT	AttributeOperand = NodeId: 12:FeedingScheduleType, BrowsePath “.”, Attribute: NodeId Alias: FST	AttributeOperand = NodeId: 12:HasSchedule, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’
6	Equals	AttributeOperand = NodeId: 12:PersonType BrowsePath 12:Zipcode “.”, Attribute: Value	LiteralOperand = ‘02138’
7	Equals	AttributeOperand = NodeId: 12:PersonType BrowsePath “12:HasPet>12:AnimalType<12:HasSchedule>12: FeedingSchedule/12:Period”, Attribute: Value Alias: FST	LiteralOperand = ‘Daily’
8	Equals	AttributeOperand = NodeId: 12:PersonType BrowsePath “12:HasPet>12:AnimalType<12:HasSchedule>12: FeedingSchedule/12:Period”, Attribute: Value Alias: FST	LiteralOperand = ‘Hourly’
9	Greater Than	AttributeOperand = NodeId: 12:PersonType BrowsePath “12:HasPet>12:AnimalType<12:HasSchedule>12: FeedingSchedule/12:Amount”, Attribute: Value Alias: FST	ElementOperand = 10
10	Cast	LiteralOperand = 10	AttributeOperand = NodeId: Int32, BrowsePath “.”, Attribute: NodeId

The results from this query would contain the QueryDataSetsshown inTable B.11.

Table B.11– Example 3 QueryDataSets

NodeId	TypeDefinition NodeId	RelativePath	Value
12:30 (JFamily1)	PersonType	“.12:LastName”	Jones
		“<12:HasPet>12:PersonType. 12:Name”	Rosemary
		“<12:HasPet>12:PersonType. 12:Name”	Basil
		“<12:HasPet>12:AnimalType<12:HasSchedule>12:FeedingSchedule. 12:Period”	Hourly
			Daily

NOTE The RelativePath column and browse name (in parentheses in the NodeIdcolumn) are not in the QueryDataSetand are only shown here for clarity. The TypeDefinition NodeIdwould be an integer not the symbolic name that is included in the table.

B.2.7 Example 4

The fourth example provides an illustration of the Hop parameter that is part of the RelatedTo Operator.

Example 4: Get PersonType.LastName where a person has a child who has a child who has a pet.

Table B.12describes the NodeTypeDescription parameters used in the example.

Table B.12– Example 4 NodeTypeDescription

Type Definition Node	Include Subtypes	QueryDataDescription
		Relative Path	Attribute		Index Range
PersonType	FALSE	“.12:LastName”	value	N/A

The corresponding ContentFilteris illustrated in Figure B.8.

Figure B.8– Example 4 filter logic tree

Table B.13describes the elements, operators and operands used in the example.

Table B.13– Example 4 ContentFilter

Element[]	Operator	Operand[0]	Operand[1]	Operand[2]	Operand[3]
0	RelatedTo	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId	Element Operand = 1	AttributeOperand = NodeId: 12:HasChild, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘2’
1	RelatedTo	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:AnimalType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:HasPet, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’

The results from this query would contain the QueryDataSetsshown in Table B.14. It is worth noting that the pig “Pig1” is referenced as a pet by Sara, but is referenced as a farm animal by Sara’s parent Paul.

Table B.14– Example 4 QueryDataSets

NodeId	TypeDefinition NodeId	RelativePath	Value
12:42 (HFamily1)	PersonType	“.12:LastName”	Hervey

NOTE The RelativePath column and browse name (in parentheses in the NodeIdcolumn) are not in the QueryDataSetand are only shown here for clarity. The TypeDefinition NodeId would be an integer not the symbolic name that is included in the table.

B.2.8 Example 5

The fifth example provides an illustration of the use of alias.

Example 5: Get the last names of children that have the same first name as a parent of theirs

Table B.15describes the NodeTypeDescription parameters used in the example.

Table B.15– Example 5 NodeTypeDescription

Type Definition Node	Include Subtypes	QueryDataDescription
		Relative Path		Attribute	Index Range
PersonType	FALSE	“<12:HasChild>12:PersonType. 12:LastName”	Value		N/A

The corresponding ContentFilteris illustrated in Figure B.9.

Figure B.9– Example 5 filter logic tree

In this example, one Referenceto PersonType is aliased to “Parent” and another Referenceto PersonType is aliased to “Child”. The value of Parent.firstName and Child.firstName are then compared. Table B.16describes the elements, operators and operands used in the example.

Table B.16– Example 5 ContentFilter

Element[]	Operator	Operand[0]	Operand[1]	Operand[2]	Operand[3}
0	And	ElementOperand = 1	ElementOperand = 2
1	RelatedTo	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId, Alias: “Parent”	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId, Alias: “Child”	AttributeOperand = NodeId: 12:HasChild, Attribute: NodeId	LiteralOperand = “1”
2	Equals	AttributeOperand = NodeId: 12:PersonType, BrowsePath ““/12:FirstName”, Attribute: Value, Alias: “Parent”	AttributeOperand = NodeId: 12:PersonType, BrowsePath ““/12:FirstName”, Attribute: Value, Alias: “Child”

The results from this query would contain the QueryDataSetsshownin Table B.17.

Table B.17– Example 5 QueryDataSets

NodeId	TypeDefinition NodeId	RelativePath	Value
12:42 (HFamily1)	PersonType	“<12:HasChild>12:PersonType.12:LastName”	Hervey

B.2.9 Example 6

The sixth example provides an illustration a different type of request, one in which the Clientis interested in displaying part of the AddressSpaceof the Server. This request includes listing a Referenceas something that is to be returned.

Example 6: Get PersonType.NodeId, AnimalType.NodeId, PersonType.HasChild Reference, PersonType.HasAnimal Reference where a person has a child who has a Animal.

Table B.18describes the NodeTypeDescription parameters used in the example.

Table B.18– Example 6 NodeTypeDescription

Type Definition Node	Include Subtypes	QueryDataDescription
Type Definition Node	Include Subtypes	Relative Path	Attribute	Index Range
PersonType	FALSE	“.12:NodeId”	value	N/A
		<12:HasChild>12:PersonType<12:HasAnimal>12:AnimalType.NodeId	value	N/A
		<12:HasChild>	value	N/A
		<12:HasChild>12:PersonType<12:HasAnimal>	value	N/A

The corresponding ContentFilteris illustrated in Figure B.10.

Figure B.10– Example 6 filter logic tree

Table B.19describes the elements, operators and operands used in the example.

Table B.19– Example 6 ContentFilter

Element[]	Operator	Operand[0]	Operand[1]	Operand[2]	Operand[3]
0	RelatedTo	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId	ElementOperand = 1	AttributeOperand = Node: 12:HasChild, BrowsePath “.”,Attribute:NodeId	LiteralOperand = ‘1’
1	RelatedTo	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:AnimalType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:HasAnimal, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’

The results from this query would contain the QueryDataSetsshownin Table B.20.

Table B.20– Example 6 QueryDataSets

NodeId	TypeDefinition NodeId	RelativePath	Value
12:42 (HFamily1)	PersonType	“.NodeId”	12:42 (HFamily1)
		<12:HasChild>12:PersonType<12:HasAnimal> 12:AnimalType.NodeId	12:91 (Pig1)
		<12:HasChild>	HasChild ReferenceDescription
		<12:HasChild>12:PersonType<12:HasAnimal>	HasFarmAnimal ReferenceDescription
12:48 (HFamily2)	PersonType	“.NodeId”	12:48 (HFamily2)
		<12:HasChild>12:PersonType<12:HasAnimal> 12:AnimalType.NodeId	12:91 (Pig1)
		<12:HasChild>	HasChild ReferenceDescription
		<12:HasChild>12:PersonType<12:HasAnimal>	HasPet ReferenceDescription

NOTE The RelativePathand browse name (in parentheses) is not in the QueryDataSetand is only shown here for clarity and the TypeDefinition NodeIdwould be an integer, not the symbolic name that is included in the table. The value field would in this case be the NodeIdwhere it was requested, but for the example the browse name is provided in parentheses and in the case of Referencetypes on the browse name is provided. For the Referenceslisted in Table B.20, the value would be a ReferenceDescription which are described in 7.30.

Table B.21provides an example of the same QueryDataSet as shown in Table B.20without any additional fields and minimal symbolic Ids. There is an entry for each requested Attribute, in the cases where an Attribute would return multiple entries the entries are separated by comas. If a structure is being returned then the structure is enclosed in square brackets. In the case of a ReferenceDescription the structure contains a structure and DisplayName and BrowseName are assumed to be the same and defined in Figure B.4.

Table B.21– Example 6 QueryDataSets without additional information

NodeId	TypeDefinition NodeId	Value
12:42	PersonType	12:42
		12:91
		[HasChild,TRUE,[48,HFamily2,HFamily2,PersonType]],
		[HasFarmAnimal,TRUE[91,Pig1,Pig1,PigType]
12:48	PersonType	12:54
		12:91
		[HasChild,TRUE,[ 54,HFamily3,HFamily3,PersonType]]
		[HasPet, TRUE,[ 91,Pig1,Pig1,PigType]]

The PersonType, HasChild, PigType, HasPet, HasFarmAnimal identifiers used in the above table would be translated to actual ExpandedNodeId.

B.2.10 Example 7

The seventh example provides an illustration a request in which a Clientwants to display part of the AddressSpacebased on a starting point that was obtained via browsing. This request includes listing Referencesas something that is to be returned. In this case the Person Browsed to Area2 and wanted to Queryfor information below this starting point.

Example 7: Get PersonType.NodeId, AnimalType.NodeId, PersonType.HasChild Reference, PersonType.HasAnimal Reference where the person is in Area2 (Cleveland nodes) and the person has a child.

Table B.22describes the NodeTypeDescription parameters used in the example.

Table B.22– Example 7 NodeTypeDescription

Type Definition Node	Include Subtypes	QueryDataDescription
Type Definition Node	Include Subtypes	Relative Path	Attribute	Index Range
PersonType	FALSE	“.NodeId”	Value	N/A
		<12:HasChild>	Value	N/A
		<12:HasAnimal>NodeId	Value	N/A
		<12:HasAnimal>	Value	N/A

The corresponding ContentFilteris illustrated in Figure B.11. Note that the Browsecall would typically return a NodeId, thus the first filter is for the BaseObjectTypewith a NodeIdof 95 where 95 is the NodeIdassociated with the Area2 node, all Nodesdescend from BaseObjectType, and NodeIdis a base Propertyso this filter will work for all Queriesof this nature.

Figure B.11– Example 7 filter logic tree

Table B.23describes the elements, operators and operands used in the example.

Table B.23– Example 7 ContentFilter

Element[]	Operator	Operand[0]	Operand[1]	Operand[2]	Operand[3]
0	RelatedTo	ElementOperand = 2	ElementOperand = 1	AttributeOperand = Node:HierachicalReference, BrowsePath “.”, Attribute:NodeId	LiteralOperand = ‘1’
1	RelatedTo	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:HasChild, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’
2	Equals	AttributeOperand = NodeId: BaseObjectType, BrowsePath “.”, Attribute: NodeId,	LiteralOperand = ‘95

The results from this Querywould contain the QueryDataSetsshownin Table B.24.

Table B.24– Example 7 QueryDataSets

NodeId	TypeDefinition NodeId	RelativePath	Value
12:42 (HFamily1)	PersonType	“.NodeId”	12:42 (HFamily1)
		<12:HasChild>	HasChild ReferenceDescription
		<12:HasAnimal>12:AnimalType.NodeId	NULL
		<12:HasAnimal>	HasFarmAnimal ReferenceDescription
12:48 (HFamily2)	PersonType	“.NodeId”	12:48 (HFamily2)
		<12:HasChild>	HasChild ReferenceDescription
		<12:HasAnimal>12:AnimalType.NodeId	12:91 (Pig1)
		<12:HasAnimal>	HasFarmAnimal ReferenceDescription

NOTE The RelativePathand browse name (in parentheses) is not in the QueryDataSetand is only shown here for clarity and the TypeDefinition NodeIdwould be an integer not the symbolic name that is included in the table. The value field would in this case be the NodeIdwhere it was requested, but for the example the browse name is provided in parentheses and in the case of Referencetypes on the browse name is provided. For the Referenceslisted in Table B.24, the value would be a ReferenceDescription which are described in 7.30.

B.2.11 Example 8

The eighth example provides an illustration of a request in which the AddressSpaceis restricted by a Serverdefined View. This request is the same as in the second example which illustrates receiving a list of disjoint Nodesand also illustrates that an array of results can be received. It is importantto note that all of the parameters and the ContentFilterare the same, only the View description would be specified as “View1”.

Example 8: Get PersonType.LastName, AnimalType.Name where a person has a child or (a pet is of type cat and has a feeding schedule) limited by the AddressSpacein View1.

The NodeTypeDescription parameters used in the example are described in Table B.25

Table B.25– Example 8 NodeTypeDescription

Type Definition Node	Include Subtypes	QueryDataDescription
Type Definition Node	Include Subtypes	Relative Path	Attribute	Index Range
PersonType	FALSE	“.12:LastName”	value	N/A
AnimalType	TRUE	“12.Name”	value	N/A

The corresponding ContentFilteris illustrated in Figure B.12.

Figure B.12– Example 8 filter logic tree

Table B.26describes the elements, operators and operands used in the example. It is worth noting that a CatType is a subtype of AnimalType.

Table B.26– Example 8 ContentFilter

Element[]	Operator	Operand[0]	Operand[1]	Operand[2]	Operand[3]
0	Or	ElementOperand=1	ElementOperand = 2
1	RelatedTo	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:HasChild, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’
2	RelatedTo	AttributeOperand = NodeId: 12:CatType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:FeedingScheduleType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:HasSchedule, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’

The results from this query would contain the QueryDataSetsshown in Table B.27. If this is compared to the result set from example 2, the only difference is the omission of the Cat Nodes. These Nodesare not in the Viewand thus are not included in the result set.

Table B.27– Example 8 QueryDataSets

NodeId	TypeDefinition NodeId	RelativePath	Value
12:30 (Jfamily1)	Persontype	.12:LastName	Jones

B.2.12 Example 9

The ninth example provides a further illustration for a request in which the AddressSpaceis restricted by a Serverdefined View. This request is similar to the second example except that some of the requested nodes are expressed in terms of a relative path. It is importantto note that the ContentFilteris the same, only the View description would be specified as “View1”.

Example 9: Get PersonType.LastName, AnimalType.Name where a person has a child or (a pet is of type cat and has a feeding schedule) limited by the AddressSpacein View1.

Table B.28describes the NodeTypeDescription parameters used in the example.

Table B.28– Example 9 NodeTypeDescription

Type Definition Node	Include Subtypes	QueryDataDescription
		Relative Path	Attribute		Index Range
PersonType	FALSE	“.NodeId”		value		N/A
		<12:HasChild>12:PersonType<12:HasAnimal>12:AnimalType.NodeId		value		N/A
		<12:HasChild>		value		N/A
		<12:HasChild>12:PersonType <12:HasAnimal>		value		N/A
PersonType	FALSE	“.12:LastName”		value		N/A
		<12:HasAnimal>12:AnimalType. 12:Name		value		N/A
AnimalType	TRUE	“.12:name”		value		N/A

The corresponding ContentFilteris illustrated in Figure B.13.

Figure B.13– Example 9 filter logic tree

Table B.29describes the elements, operators and operands used in the example.

Table B.29– Example 9 ContentFilter

Element[]	Operator	Operand[0]	Operand[1]	Operand[2]	Operand[3]
0	Or	ElementOperand=1	ElementOperand = 2
1	RelatedTo	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:PersonType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:HasChild, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’
2	RelatedTo	AttributeOperand = NodeId: 12:CatType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:FeedingScheduleType, BrowsePath “.”, Attribute: NodeId	AttributeOperand = NodeId: 12:HasSchedule, BrowsePath “.”, Attribute: NodeId	LiteralOperand = ‘1’

The results from this Querywould contain the QueryDataSetsshown in Table B.30. If this is compared to the result set from example 2, the Pet Nodesare included in the list, even though they are outside of the View. This is possible since the name referenced via the relative path and the root Nodeis in the View.

Table B.30– Example 9 QueryDataSets

NodeId	TypeDefinition NodeId	RelativePath	Value
12:30 (Jfamily1)	PersonType	. 12:LastName	Jones
		<12:HasAnimal>12:AnimalType. 12:Name	Rosemary
		<12:HasAnimal>12:AnimalType. 12:Name	Basil

NOTE The RelativePath column and browse name (in parentheses in the NodeIdcolumn) are not in the QueryDataSet and are only shown here for clarity. The TypeDefinition NodeId would be an integer not the symbolic name that is included in the table.

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