UA Part 4: Services - 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.15 describes the NodeTypeDescription parameters used in the example.

Table B.15 – Example 5 NodeTypeDescription

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

The corresponding ContentFilter is illustrated in Figure B.9.

Figure B.9 – Example 5 filter logic tree

In this example, one Reference to PersonType is aliased to “Parent” and another Reference to PersonType is aliased to “Child”. The value of Parent.firstName and Child.firstName are then compared. Table B.16 describes 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 QueryDataSets shown in 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

NOTE The RelativePath column and browse name (in parentheses in the NodeId column) 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.